Original Research

Financial relationships between physicians and industry are prevalent and complex and may have implications for patient care. A 2007 study reported that 94% of 3167 physicians surveyed had established some form of paid relationship with companies in the pharmaceutical industry.¹ To facilitate increased transparency around these relationships, lawmakers passed the Physician Payments Sunshine Act in 2010, which requires pharmaceutical companies and device manufacturers to report all payments made to physicians.² Mandatory disclosures include meals, honoraria, travel expenses, grants, and ownership or investment interests greater than $10. The information is displayed publicly in the Open Payments database (OPD)(https://openpayments-data.cms.gov/), a platform run by the Centers for Medicare and Medicaid Services.

The OPD allows for in-depth analyses of industry payments made to physicians. Many medical specialties—including orthopedics,^3-5 plastic surgery,^6,7 ophthalmology,⁸ and gastroenterology⁹—have published extensive literature characterizing the nature of these payments and disparities in the distribution of payments based on sex, geographic distribution, and other factors. After the first full year of OPD data collection for dermatology in 2014, Feng et al¹⁰ examined the number, amount, and nature of industry payments to dermatologists, as well as their geographic distribution for that year. As a follow-up to this initial research, Schlager et al¹¹ characterized payments made to dermatologists for the year 2016 and found an increase in the total payments, mean payments, and number of dermatologists receiving payments compared with the 2014 data.

Our study aimed to characterize the last 5 years of available OPD data—from January 1, 2017, to December 31, 2021—to further explore trends in industry payments made to dermatologists. In particular, we examined the effects of the COVID-19 pandemic on payments as well as sex disparities and the distribution of industry payments.

Methods

We performed a retrospective analysis of the OPD for the general payment datasets from January 1, 2017, to December 31, 2021. The results were filtered to include only payments made to dermatologists, excluding physicians from other specialties, physician assistants, and other types of practitioners. Data for each physician were grouped by National Provider Identifier (NPI) for providers included in the set, allowing for analysis at the individual level. Data on sex were extracted from the National Plan & Provider Enumeration System’s monthly data dissemination for NPIs for July 2023 (when the study was conducted) and were joined to the OPD data using the NPI number reported for each physician. All data were extracted, transformed, and analyzed using R software (version 4.2.1). Figures and visualizations were produced using Microsoft Excel 2016.

Results

In 2017, a total of 358,884 payments were made by industry to dermatologists, accounting for nearly $58.0 million. The mean total value of payments received per dermatologist was $5231.74, and the mean payment amount was $161.49. In 2018, the total number of payments increased year-over-year by 5.5% (378,509 payments), the total value of payments received increased by 7.5% (approximately $62.3 million), and the mean total value of payments received per dermatologist increased by 5.3% ($5508.98). In 2019, the total number of payments increased by 3.0% (389,670 total payments), the total value of payments recieved increased by 13.2% (approximately $70.5 million), and the mean total value of payments received per dermatologist increased by 11.3% ($6133.45). All of these values decreased in 2020, likely due to COVID-19–related restrictions on travel and meetings (total number of payments, 208,470 [−46.5%]; total value of payments received, approximately $37.5 million [−46.9%], mean total value of payments received per dermatologist, $3757.27 [−38.7%]), but the mean payment amount remained stable at $179.47. In 2021, the total number of payments (295,808 [+41.9%]), total value of payments received (approximately $50.3 million [+34.4%]), and mean total value of payments received per dermatologist ($4707.88 [+25.3%]) all rebounded, but not to pre-2020 levels (Table 1). When looking at the geographic distribution of payments, the top 5 states receiving the highest total value of payments during the study period included California ($41.51 million), New York ($32.26 million), Florida ($21.38 million), Texas ($19.93 million), and Pennsylvania ($11.69 million).

For each year from 2017 to 2021, more than 80% of payments made to dermatologists were less than $50. The majority (60.7%–75.8%) were in the $10 to $50 range. Between 4% and 5% of payments were more than $1000 for each year. Fewer than 10% of dermatologists received more than $5000 in total payments per year. Most dermatologists (33.3%–36.9%) received $100 to $500 per year. The distribution of payments stratified by number of payments made by amount and payment amount per dermatologist is further delineated in Table 2.

Among dermatologists who received industry payments in 2017, slightly more than half (50.9%) were male; however, male dermatologists accounted for more than $40.1 million of the more than $57.6 million total payments made to dermatologists (69.6%) that year. Male dermatologists received a mean payment amount of $198.26, while female dermatologists received a significantly smaller amount of $113.52 (P<.001). The mean total value of payments received per male dermatologist was $7204.36, while the mean total value for female dermatologists was $3272.16 (P<.001). The same statistically significant disparities in mean payment amount and mean total value of payments received by male vs female dermatologists were observed for every year from 2017 through 2021 (Table 3).

 

Comment

Benefits of Physician Relationships With Industry—The Physician Payments Sunshine Act increased transparency of industry payments to physicians by creating the OPD through which these relationships can be reported.¹² The effects of these relationships on treatment practices have been the subject of many studies in recent years. Some have suggested that industry ties may impact prescription patterns of endorsed medications.¹³ It also has been reported that the chance of a research study identifying a positive outcome for a particular treatment is higher when the study is funded by a pharmaceutical company compared to other sponsors.¹⁴ On the other hand, some researchers have argued that, when established and maintained in an ethical manner, industry-physician relationships may help practitioners stay updated on the newest treatment paradigms and benefit patient care.¹⁵ Industry relationships may help drive innovation of new products with direct input from frontline physicians who take care of the patients these products aim to help.

Limitations of the OPD—Critics of the OPD have argued that the reported data lack sufficient context and are not easily interpretable by most patients.¹⁶ In addition, many patients might not know about the existence of the database. Indeed, one national survey-based study showed that only 12% of 3542 respondents knew that this information was publicly available, and only 5% knew whether their own physician had received industry payments.¹⁷

Increased Payments From Industry—Our analysis builds on previously reported data in dermatology from 2014 to 2016.^10,11 We found that the trends of increasing numbers and dollar amounts of payments made by industry to dermatologists continued from 2017 to 2019, which may reflect the intended effects of the Physician Payments Sunshine Act, as more payments are being reported in a transparent manner. It also shows that relationships between industry and dermatologists have become more commonplace over time.

It is important to consider these trends in the context of overall Medicare expenditures and prescription volumes. Between 2008 and 2021, prescription volumes have been increasing at a rate of 1% to 4% per year, with 2020 being an exception as the volume decreased slightly from the year prior due to COVID-19 (−3%). Similarly, total Medicare and Medicaid expenditures have been growing at a rate of almost 5% per year.¹⁸ Based on our study results, it appears the total value of payments made between 2017 and 2021 increased at a rate that outpaced prescription volume and expenditures; however, it is difficult to draw conclusions about the relationship between payments made to dermatologists and spending without examining prescriptions specific to dermatologists in the OPD dataset. This relationship could be further explored in future studies.

COVID-19 Restrictions Impacted Payments in 2021—We hypothesize that COVID-19–related restrictions on traveling and in-person meetings led to a decrease in the number of payments, total payment amount, and mean total value of payments received per dermatologist. Notably, compensation for services other than consulting, including speaking fees, had the most precipitous decrease in total payment amount. On the other hand, honoraria and consulting fees were least impacted, as many dermatologists were still able to maintain relationships with industry on an advisory basis without traveling. From 2020 to 2021, the number of total payments and dollar amounts increased with easing of COVID-19 restrictions; however, they had not yet rebounded to 2019 levels during the study period. It will be interesting to continue monitoring these trends once data from future years become available.

Top-Compensated Dermatologists—Our study results also show that for all years from 2017 through 2021, the majority of industry payments were made to a small concentrated percentage of top-compensated dermatologists, which may reflect larger and more frequent payments to those identified by pharmaceutical companies as thought leaders and key opinion leaders in the field or those who are more willing to establish extensive ties with industry. Similarly skewed distributions in payments have been shown in other medical subspecialties including neurosurgery, plastic surgery, otolaryngology, and orthopedics.^4,6,19,20 It also is apparent that the majority of compensated dermatologists in the OPD maintain relatively small ties with industry. For every year from 2017 to 2021, more than half of compensated dermatologists received total payments of less than $500 per year, most of which stemmed from the food and beverage category. Interestingly, a prior study showed that patient perceptions of industry-physician ties may be more strongly impacted by the payment category than the amount.²¹ For example, respondents viewed payments for meals and lodging more negatively, as they were seen more as personal gifts without direct benefit to patients. Conversely, respondents held more positive views of physicians who received free drug samples, which were perceived as benefiting patients, as well as those receiving consulting fees, which were perceived as a signal of physician expertise. Notably, in the same study, physicians who received no payments from industry were seen as honest but also were viewed by some respondents as being inexperienced or uninformed about new treatments.²¹

The contribution and public perception of dermatologists who conduct investigator-initiated research utilizing other types of funding (eg, government grants) also are important to consider but were not directly assessed within the scope of the current study.

Sex Disparities in Compensation—Multiple studies in the literature have demonstrated that sex inequities exist across medical specialties.^22,23 In dermatology, although women make up slightly more than 50% of board-certified dermatologists, they continue to be underrepresented compared with men in leadership positions, academic rank, research funding, and lectureships at national meetings.^24-27 In survey-based studies specifically examining gender-based physician compensation, male dermatologists were found to earn higher salaries than their female counterparts in both private practice and academic settings, even after adjusting for work hours, practice characteristics, and academic rank.^28,29

Our study contributes to the growing body of evidence suggesting that sex inequities also may exist with regard to financial payments from industry. Our results showed that, although the number of male and female dermatologists with industry relationships was similar each year, the number of payments made and total payment amount were both significantly (P<.001) higher for male dermatologists from 2017 through 2021. In 2021, the mean payment amount ($201.57 for male dermatologists; $117.73 for female dermatologists) and mean total amount of payments received ($6172.89 and $2957.79, respectively) also were significantly higher for male compared with female dermatologists (P<.001). The cause of this disparity likely is multifactorial and warrants additional studies in the future. One hypothesis in the existing literature is that male physicians may be more inclined to seek out relationships with industry; it also is possible that disparities in research funding, academic rank, and speaking opportunities at national conferences detailed previously may contribute to inequities in industry payments as companies seek out perceived leaders in the field.³⁰

Limitations and Future Directions—Several important limitations of our study warrant further consideration. As with any database study, the accuracy of the results presented and the conclusions drawn are highly dependent on the precision of the available data, which is reliant on transparent documentation by pharmaceutical companies and physicians. There are no independent methods of verifying the information reported. There have been reports in the literature questioning the utility of the OPD data and risk for misinterpretation.^16,31 Furthermore, the OPD only includes companies whose products are covered by government-sponsored programs, such as Medicare and Medicaid, and therefore does not encompass the totality of industry-dermatologist relationships. We also focused specifically on board-certified dermatologists and did not analyze the extent of industry relationships involving residents, nurses, physician assistants, and other critical members of health care teams that may impact patient care. Differences between academic and private practice payments also could not be examined using the OPD but could present an interesting area for future studies.

Despite these limitations, our study was extensive, using the publicly available OPD to analyze trends and disparities in financial relationships between dermatologists and industry partners from 2017 through 2021. Notably, these findings are not intended to provide judgment or seek to tease out financial relationships that are beneficial for patient care from those that are not; rather, they are intended only to lend additional transparency, provoke thought, and encourage future studies and discussion surrounding this important topic.

Conclusion

Financial relationships between dermatologists and industry are complex and are becoming more prevalent, as shown in our study. These relationships may be critical to facilitate novel patient-centered research and growth in the field of dermatology; however, they also have the potential to be seen as bias in patient care. Transparent reporting of these relationships is an important step in future research regarding the effects of different payment types and serves as the basis for further understanding industry-dermatologist relationships as well as any inequities that exist in the distribution of payments. We encourage all dermatologists to review their public profiles in the OPD. Physicians have the opportunity to review all payment data reported by companies and challenge the accuracy of the data if necessary.

Financial relationships between physicians and industry are prevalent and complex and may have implications for patient care. A 2007 study reported that 94% of 3167 physicians surveyed had established some form of paid relationship with companies in the pharmaceutical industry.¹ To facilitate increased transparency around these relationships, lawmakers passed the Physician Payments Sunshine Act in 2010, which requires pharmaceutical companies and device manufacturers to report all payments made to physicians.² Mandatory disclosures include meals, honoraria, travel expenses, grants, and ownership or investment interests greater than $10. The information is displayed publicly in the Open Payments database (OPD)(https://openpayments-data.cms.gov/), a platform run by the Centers for Medicare and Medicaid Services.

The OPD allows for in-depth analyses of industry payments made to physicians. Many medical specialties—including orthopedics,^3-5 plastic surgery,^6,7 ophthalmology,⁸ and gastroenterology⁹—have published extensive literature characterizing the nature of these payments and disparities in the distribution of payments based on sex, geographic distribution, and other factors. After the first full year of OPD data collection for dermatology in 2014, Feng et al¹⁰ examined the number, amount, and nature of industry payments to dermatologists, as well as their geographic distribution for that year. As a follow-up to this initial research, Schlager et al¹¹ characterized payments made to dermatologists for the year 2016 and found an increase in the total payments, mean payments, and number of dermatologists receiving payments compared with the 2014 data.

Our study aimed to characterize the last 5 years of available OPD data—from January 1, 2017, to December 31, 2021—to further explore trends in industry payments made to dermatologists. In particular, we examined the effects of the COVID-19 pandemic on payments as well as sex disparities and the distribution of industry payments.

Methods

We performed a retrospective analysis of the OPD for the general payment datasets from January 1, 2017, to December 31, 2021. The results were filtered to include only payments made to dermatologists, excluding physicians from other specialties, physician assistants, and other types of practitioners. Data for each physician were grouped by National Provider Identifier (NPI) for providers included in the set, allowing for analysis at the individual level. Data on sex were extracted from the National Plan & Provider Enumeration System’s monthly data dissemination for NPIs for July 2023 (when the study was conducted) and were joined to the OPD data using the NPI number reported for each physician. All data were extracted, transformed, and analyzed using R software (version 4.2.1). Figures and visualizations were produced using Microsoft Excel 2016.

Results

In 2017, a total of 358,884 payments were made by industry to dermatologists, accounting for nearly $58.0 million. The mean total value of payments received per dermatologist was $5231.74, and the mean payment amount was $161.49. In 2018, the total number of payments increased year-over-year by 5.5% (378,509 payments), the total value of payments received increased by 7.5% (approximately $62.3 million), and the mean total value of payments received per dermatologist increased by 5.3% ($5508.98). In 2019, the total number of payments increased by 3.0% (389,670 total payments), the total value of payments recieved increased by 13.2% (approximately $70.5 million), and the mean total value of payments received per dermatologist increased by 11.3% ($6133.45). All of these values decreased in 2020, likely due to COVID-19–related restrictions on travel and meetings (total number of payments, 208,470 [−46.5%]; total value of payments received, approximately $37.5 million [−46.9%], mean total value of payments received per dermatologist, $3757.27 [−38.7%]), but the mean payment amount remained stable at $179.47. In 2021, the total number of payments (295,808 [+41.9%]), total value of payments received (approximately $50.3 million [+34.4%]), and mean total value of payments received per dermatologist ($4707.88 [+25.3%]) all rebounded, but not to pre-2020 levels (Table 1). When looking at the geographic distribution of payments, the top 5 states receiving the highest total value of payments during the study period included California ($41.51 million), New York ($32.26 million), Florida ($21.38 million), Texas ($19.93 million), and Pennsylvania ($11.69 million).

For each year from 2017 to 2021, more than 80% of payments made to dermatologists were less than $50. The majority (60.7%–75.8%) were in the $10 to $50 range. Between 4% and 5% of payments were more than $1000 for each year. Fewer than 10% of dermatologists received more than $5000 in total payments per year. Most dermatologists (33.3%–36.9%) received $100 to $500 per year. The distribution of payments stratified by number of payments made by amount and payment amount per dermatologist is further delineated in Table 2.

Among dermatologists who received industry payments in 2017, slightly more than half (50.9%) were male; however, male dermatologists accounted for more than $40.1 million of the more than $57.6 million total payments made to dermatologists (69.6%) that year. Male dermatologists received a mean payment amount of $198.26, while female dermatologists received a significantly smaller amount of $113.52 (P<.001). The mean total value of payments received per male dermatologist was $7204.36, while the mean total value for female dermatologists was $3272.16 (P<.001). The same statistically significant disparities in mean payment amount and mean total value of payments received by male vs female dermatologists were observed for every year from 2017 through 2021 (Table 3).

 

Comment

Benefits of Physician Relationships With Industry—The Physician Payments Sunshine Act increased transparency of industry payments to physicians by creating the OPD through which these relationships can be reported.¹² The effects of these relationships on treatment practices have been the subject of many studies in recent years. Some have suggested that industry ties may impact prescription patterns of endorsed medications.¹³ It also has been reported that the chance of a research study identifying a positive outcome for a particular treatment is higher when the study is funded by a pharmaceutical company compared to other sponsors.¹⁴ On the other hand, some researchers have argued that, when established and maintained in an ethical manner, industry-physician relationships may help practitioners stay updated on the newest treatment paradigms and benefit patient care.¹⁵ Industry relationships may help drive innovation of new products with direct input from frontline physicians who take care of the patients these products aim to help.

Limitations of the OPD—Critics of the OPD have argued that the reported data lack sufficient context and are not easily interpretable by most patients.¹⁶ In addition, many patients might not know about the existence of the database. Indeed, one national survey-based study showed that only 12% of 3542 respondents knew that this information was publicly available, and only 5% knew whether their own physician had received industry payments.¹⁷

Increased Payments From Industry—Our analysis builds on previously reported data in dermatology from 2014 to 2016.^10,11 We found that the trends of increasing numbers and dollar amounts of payments made by industry to dermatologists continued from 2017 to 2019, which may reflect the intended effects of the Physician Payments Sunshine Act, as more payments are being reported in a transparent manner. It also shows that relationships between industry and dermatologists have become more commonplace over time.

It is important to consider these trends in the context of overall Medicare expenditures and prescription volumes. Between 2008 and 2021, prescription volumes have been increasing at a rate of 1% to 4% per year, with 2020 being an exception as the volume decreased slightly from the year prior due to COVID-19 (−3%). Similarly, total Medicare and Medicaid expenditures have been growing at a rate of almost 5% per year.¹⁸ Based on our study results, it appears the total value of payments made between 2017 and 2021 increased at a rate that outpaced prescription volume and expenditures; however, it is difficult to draw conclusions about the relationship between payments made to dermatologists and spending without examining prescriptions specific to dermatologists in the OPD dataset. This relationship could be further explored in future studies.

COVID-19 Restrictions Impacted Payments in 2021—We hypothesize that COVID-19–related restrictions on traveling and in-person meetings led to a decrease in the number of payments, total payment amount, and mean total value of payments received per dermatologist. Notably, compensation for services other than consulting, including speaking fees, had the most precipitous decrease in total payment amount. On the other hand, honoraria and consulting fees were least impacted, as many dermatologists were still able to maintain relationships with industry on an advisory basis without traveling. From 2020 to 2021, the number of total payments and dollar amounts increased with easing of COVID-19 restrictions; however, they had not yet rebounded to 2019 levels during the study period. It will be interesting to continue monitoring these trends once data from future years become available.

Top-Compensated Dermatologists—Our study results also show that for all years from 2017 through 2021, the majority of industry payments were made to a small concentrated percentage of top-compensated dermatologists, which may reflect larger and more frequent payments to those identified by pharmaceutical companies as thought leaders and key opinion leaders in the field or those who are more willing to establish extensive ties with industry. Similarly skewed distributions in payments have been shown in other medical subspecialties including neurosurgery, plastic surgery, otolaryngology, and orthopedics.^4,6,19,20 It also is apparent that the majority of compensated dermatologists in the OPD maintain relatively small ties with industry. For every year from 2017 to 2021, more than half of compensated dermatologists received total payments of less than $500 per year, most of which stemmed from the food and beverage category. Interestingly, a prior study showed that patient perceptions of industry-physician ties may be more strongly impacted by the payment category than the amount.²¹ For example, respondents viewed payments for meals and lodging more negatively, as they were seen more as personal gifts without direct benefit to patients. Conversely, respondents held more positive views of physicians who received free drug samples, which were perceived as benefiting patients, as well as those receiving consulting fees, which were perceived as a signal of physician expertise. Notably, in the same study, physicians who received no payments from industry were seen as honest but also were viewed by some respondents as being inexperienced or uninformed about new treatments.²¹

The contribution and public perception of dermatologists who conduct investigator-initiated research utilizing other types of funding (eg, government grants) also are important to consider but were not directly assessed within the scope of the current study.

Sex Disparities in Compensation—Multiple studies in the literature have demonstrated that sex inequities exist across medical specialties.^22,23 In dermatology, although women make up slightly more than 50% of board-certified dermatologists, they continue to be underrepresented compared with men in leadership positions, academic rank, research funding, and lectureships at national meetings.^24-27 In survey-based studies specifically examining gender-based physician compensation, male dermatologists were found to earn higher salaries than their female counterparts in both private practice and academic settings, even after adjusting for work hours, practice characteristics, and academic rank.^28,29

Our study contributes to the growing body of evidence suggesting that sex inequities also may exist with regard to financial payments from industry. Our results showed that, although the number of male and female dermatologists with industry relationships was similar each year, the number of payments made and total payment amount were both significantly (P<.001) higher for male dermatologists from 2017 through 2021. In 2021, the mean payment amount ($201.57 for male dermatologists; $117.73 for female dermatologists) and mean total amount of payments received ($6172.89 and $2957.79, respectively) also were significantly higher for male compared with female dermatologists (P<.001). The cause of this disparity likely is multifactorial and warrants additional studies in the future. One hypothesis in the existing literature is that male physicians may be more inclined to seek out relationships with industry; it also is possible that disparities in research funding, academic rank, and speaking opportunities at national conferences detailed previously may contribute to inequities in industry payments as companies seek out perceived leaders in the field.³⁰

Limitations and Future Directions—Several important limitations of our study warrant further consideration. As with any database study, the accuracy of the results presented and the conclusions drawn are highly dependent on the precision of the available data, which is reliant on transparent documentation by pharmaceutical companies and physicians. There are no independent methods of verifying the information reported. There have been reports in the literature questioning the utility of the OPD data and risk for misinterpretation.^16,31 Furthermore, the OPD only includes companies whose products are covered by government-sponsored programs, such as Medicare and Medicaid, and therefore does not encompass the totality of industry-dermatologist relationships. We also focused specifically on board-certified dermatologists and did not analyze the extent of industry relationships involving residents, nurses, physician assistants, and other critical members of health care teams that may impact patient care. Differences between academic and private practice payments also could not be examined using the OPD but could present an interesting area for future studies.

Despite these limitations, our study was extensive, using the publicly available OPD to analyze trends and disparities in financial relationships between dermatologists and industry partners from 2017 through 2021. Notably, these findings are not intended to provide judgment or seek to tease out financial relationships that are beneficial for patient care from those that are not; rather, they are intended only to lend additional transparency, provoke thought, and encourage future studies and discussion surrounding this important topic.

Conclusion

Financial relationships between dermatologists and industry are complex and are becoming more prevalent, as shown in our study. These relationships may be critical to facilitate novel patient-centered research and growth in the field of dermatology; however, they also have the potential to be seen as bias in patient care. Transparent reporting of these relationships is an important step in future research regarding the effects of different payment types and serves as the basis for further understanding industry-dermatologist relationships as well as any inequities that exist in the distribution of payments. We encourage all dermatologists to review their public profiles in the OPD. Physicians have the opportunity to review all payment data reported by companies and challenge the accuracy of the data if necessary.

Financial relationships between physicians and industry are prevalent and complex and may have implications for patient care. A 2007 study reported that 94% of 3167 physicians surveyed had established some form of paid relationship with companies in the pharmaceutical industry.¹ To facilitate increased transparency around these relationships, lawmakers passed the Physician Payments Sunshine Act in 2010, which requires pharmaceutical companies and device manufacturers to report all payments made to physicians.² Mandatory disclosures include meals, honoraria, travel expenses, grants, and ownership or investment interests greater than $10. The information is displayed publicly in the Open Payments database (OPD)(https://openpayments-data.cms.gov/), a platform run by the Centers for Medicare and Medicaid Services.

The OPD allows for in-depth analyses of industry payments made to physicians. Many medical specialties—including orthopedics,^3-5 plastic surgery,^6,7 ophthalmology,⁸ and gastroenterology⁹—have published extensive literature characterizing the nature of these payments and disparities in the distribution of payments based on sex, geographic distribution, and other factors. After the first full year of OPD data collection for dermatology in 2014, Feng et al¹⁰ examined the number, amount, and nature of industry payments to dermatologists, as well as their geographic distribution for that year. As a follow-up to this initial research, Schlager et al¹¹ characterized payments made to dermatologists for the year 2016 and found an increase in the total payments, mean payments, and number of dermatologists receiving payments compared with the 2014 data.

Our study aimed to characterize the last 5 years of available OPD data—from January 1, 2017, to December 31, 2021—to further explore trends in industry payments made to dermatologists. In particular, we examined the effects of the COVID-19 pandemic on payments as well as sex disparities and the distribution of industry payments.

Methods

We performed a retrospective analysis of the OPD for the general payment datasets from January 1, 2017, to December 31, 2021. The results were filtered to include only payments made to dermatologists, excluding physicians from other specialties, physician assistants, and other types of practitioners. Data for each physician were grouped by National Provider Identifier (NPI) for providers included in the set, allowing for analysis at the individual level. Data on sex were extracted from the National Plan & Provider Enumeration System’s monthly data dissemination for NPIs for July 2023 (when the study was conducted) and were joined to the OPD data using the NPI number reported for each physician. All data were extracted, transformed, and analyzed using R software (version 4.2.1). Figures and visualizations were produced using Microsoft Excel 2016.

Results

In 2017, a total of 358,884 payments were made by industry to dermatologists, accounting for nearly $58.0 million. The mean total value of payments received per dermatologist was $5231.74, and the mean payment amount was $161.49. In 2018, the total number of payments increased year-over-year by 5.5% (378,509 payments), the total value of payments received increased by 7.5% (approximately $62.3 million), and the mean total value of payments received per dermatologist increased by 5.3% ($5508.98). In 2019, the total number of payments increased by 3.0% (389,670 total payments), the total value of payments recieved increased by 13.2% (approximately $70.5 million), and the mean total value of payments received per dermatologist increased by 11.3% ($6133.45). All of these values decreased in 2020, likely due to COVID-19–related restrictions on travel and meetings (total number of payments, 208,470 [−46.5%]; total value of payments received, approximately $37.5 million [−46.9%], mean total value of payments received per dermatologist, $3757.27 [−38.7%]), but the mean payment amount remained stable at $179.47. In 2021, the total number of payments (295,808 [+41.9%]), total value of payments received (approximately $50.3 million [+34.4%]), and mean total value of payments received per dermatologist ($4707.88 [+25.3%]) all rebounded, but not to pre-2020 levels (Table 1). When looking at the geographic distribution of payments, the top 5 states receiving the highest total value of payments during the study period included California ($41.51 million), New York ($32.26 million), Florida ($21.38 million), Texas ($19.93 million), and Pennsylvania ($11.69 million).

For each year from 2017 to 2021, more than 80% of payments made to dermatologists were less than $50. The majority (60.7%–75.8%) were in the $10 to $50 range. Between 4% and 5% of payments were more than $1000 for each year. Fewer than 10% of dermatologists received more than $5000 in total payments per year. Most dermatologists (33.3%–36.9%) received $100 to $500 per year. The distribution of payments stratified by number of payments made by amount and payment amount per dermatologist is further delineated in Table 2.

Among dermatologists who received industry payments in 2017, slightly more than half (50.9%) were male; however, male dermatologists accounted for more than $40.1 million of the more than $57.6 million total payments made to dermatologists (69.6%) that year. Male dermatologists received a mean payment amount of $198.26, while female dermatologists received a significantly smaller amount of $113.52 (P<.001). The mean total value of payments received per male dermatologist was $7204.36, while the mean total value for female dermatologists was $3272.16 (P<.001). The same statistically significant disparities in mean payment amount and mean total value of payments received by male vs female dermatologists were observed for every year from 2017 through 2021 (Table 3).

 

Comment

Benefits of Physician Relationships With Industry—The Physician Payments Sunshine Act increased transparency of industry payments to physicians by creating the OPD through which these relationships can be reported.¹² The effects of these relationships on treatment practices have been the subject of many studies in recent years. Some have suggested that industry ties may impact prescription patterns of endorsed medications.¹³ It also has been reported that the chance of a research study identifying a positive outcome for a particular treatment is higher when the study is funded by a pharmaceutical company compared to other sponsors.¹⁴ On the other hand, some researchers have argued that, when established and maintained in an ethical manner, industry-physician relationships may help practitioners stay updated on the newest treatment paradigms and benefit patient care.¹⁵ Industry relationships may help drive innovation of new products with direct input from frontline physicians who take care of the patients these products aim to help.

Limitations of the OPD—Critics of the OPD have argued that the reported data lack sufficient context and are not easily interpretable by most patients.¹⁶ In addition, many patients might not know about the existence of the database. Indeed, one national survey-based study showed that only 12% of 3542 respondents knew that this information was publicly available, and only 5% knew whether their own physician had received industry payments.¹⁷

Increased Payments From Industry—Our analysis builds on previously reported data in dermatology from 2014 to 2016.^10,11 We found that the trends of increasing numbers and dollar amounts of payments made by industry to dermatologists continued from 2017 to 2019, which may reflect the intended effects of the Physician Payments Sunshine Act, as more payments are being reported in a transparent manner. It also shows that relationships between industry and dermatologists have become more commonplace over time.

It is important to consider these trends in the context of overall Medicare expenditures and prescription volumes. Between 2008 and 2021, prescription volumes have been increasing at a rate of 1% to 4% per year, with 2020 being an exception as the volume decreased slightly from the year prior due to COVID-19 (−3%). Similarly, total Medicare and Medicaid expenditures have been growing at a rate of almost 5% per year.¹⁸ Based on our study results, it appears the total value of payments made between 2017 and 2021 increased at a rate that outpaced prescription volume and expenditures; however, it is difficult to draw conclusions about the relationship between payments made to dermatologists and spending without examining prescriptions specific to dermatologists in the OPD dataset. This relationship could be further explored in future studies.

COVID-19 Restrictions Impacted Payments in 2021—We hypothesize that COVID-19–related restrictions on traveling and in-person meetings led to a decrease in the number of payments, total payment amount, and mean total value of payments received per dermatologist. Notably, compensation for services other than consulting, including speaking fees, had the most precipitous decrease in total payment amount. On the other hand, honoraria and consulting fees were least impacted, as many dermatologists were still able to maintain relationships with industry on an advisory basis without traveling. From 2020 to 2021, the number of total payments and dollar amounts increased with easing of COVID-19 restrictions; however, they had not yet rebounded to 2019 levels during the study period. It will be interesting to continue monitoring these trends once data from future years become available.

Top-Compensated Dermatologists—Our study results also show that for all years from 2017 through 2021, the majority of industry payments were made to a small concentrated percentage of top-compensated dermatologists, which may reflect larger and more frequent payments to those identified by pharmaceutical companies as thought leaders and key opinion leaders in the field or those who are more willing to establish extensive ties with industry. Similarly skewed distributions in payments have been shown in other medical subspecialties including neurosurgery, plastic surgery, otolaryngology, and orthopedics.^4,6,19,20 It also is apparent that the majority of compensated dermatologists in the OPD maintain relatively small ties with industry. For every year from 2017 to 2021, more than half of compensated dermatologists received total payments of less than $500 per year, most of which stemmed from the food and beverage category. Interestingly, a prior study showed that patient perceptions of industry-physician ties may be more strongly impacted by the payment category than the amount.²¹ For example, respondents viewed payments for meals and lodging more negatively, as they were seen more as personal gifts without direct benefit to patients. Conversely, respondents held more positive views of physicians who received free drug samples, which were perceived as benefiting patients, as well as those receiving consulting fees, which were perceived as a signal of physician expertise. Notably, in the same study, physicians who received no payments from industry were seen as honest but also were viewed by some respondents as being inexperienced or uninformed about new treatments.²¹

The contribution and public perception of dermatologists who conduct investigator-initiated research utilizing other types of funding (eg, government grants) also are important to consider but were not directly assessed within the scope of the current study.

Sex Disparities in Compensation—Multiple studies in the literature have demonstrated that sex inequities exist across medical specialties.^22,23 In dermatology, although women make up slightly more than 50% of board-certified dermatologists, they continue to be underrepresented compared with men in leadership positions, academic rank, research funding, and lectureships at national meetings.^24-27 In survey-based studies specifically examining gender-based physician compensation, male dermatologists were found to earn higher salaries than their female counterparts in both private practice and academic settings, even after adjusting for work hours, practice characteristics, and academic rank.^28,29

Our study contributes to the growing body of evidence suggesting that sex inequities also may exist with regard to financial payments from industry. Our results showed that, although the number of male and female dermatologists with industry relationships was similar each year, the number of payments made and total payment amount were both significantly (P<.001) higher for male dermatologists from 2017 through 2021. In 2021, the mean payment amount ($201.57 for male dermatologists; $117.73 for female dermatologists) and mean total amount of payments received ($6172.89 and $2957.79, respectively) also were significantly higher for male compared with female dermatologists (P<.001). The cause of this disparity likely is multifactorial and warrants additional studies in the future. One hypothesis in the existing literature is that male physicians may be more inclined to seek out relationships with industry; it also is possible that disparities in research funding, academic rank, and speaking opportunities at national conferences detailed previously may contribute to inequities in industry payments as companies seek out perceived leaders in the field.³⁰

Limitations and Future Directions—Several important limitations of our study warrant further consideration. As with any database study, the accuracy of the results presented and the conclusions drawn are highly dependent on the precision of the available data, which is reliant on transparent documentation by pharmaceutical companies and physicians. There are no independent methods of verifying the information reported. There have been reports in the literature questioning the utility of the OPD data and risk for misinterpretation.^16,31 Furthermore, the OPD only includes companies whose products are covered by government-sponsored programs, such as Medicare and Medicaid, and therefore does not encompass the totality of industry-dermatologist relationships. We also focused specifically on board-certified dermatologists and did not analyze the extent of industry relationships involving residents, nurses, physician assistants, and other critical members of health care teams that may impact patient care. Differences between academic and private practice payments also could not be examined using the OPD but could present an interesting area for future studies.

Despite these limitations, our study was extensive, using the publicly available OPD to analyze trends and disparities in financial relationships between dermatologists and industry partners from 2017 through 2021. Notably, these findings are not intended to provide judgment or seek to tease out financial relationships that are beneficial for patient care from those that are not; rather, they are intended only to lend additional transparency, provoke thought, and encourage future studies and discussion surrounding this important topic.

Conclusion

Financial relationships between dermatologists and industry are complex and are becoming more prevalent, as shown in our study. These relationships may be critical to facilitate novel patient-centered research and growth in the field of dermatology; however, they also have the potential to be seen as bias in patient care. Transparent reporting of these relationships is an important step in future research regarding the effects of different payment types and serves as the basis for further understanding industry-dermatologist relationships as well as any inequities that exist in the distribution of payments. We encourage all dermatologists to review their public profiles in the OPD. Physicians have the opportunity to review all payment data reported by companies and challenge the accuracy of the data if necessary.

Pruritus, which is defined as an itching sensation that elicits a desire to scratch, is the most common cutaneous condition. Pruritus is considered chronic when it lasts for more than 6 weeks.¹ Etiologies implicated in chronic pruritus include but are not limited to primary skin diseases such as atopic dermatitis, systemic causes, neuropathic disorders, and psychogenic reasons.² In approximately 8% to 35% of patients, the cause of pruritus remains elusive despite intensive investigation.³ The mechanisms of itch are multifaceted and include complex neural pathways.⁴ Although itch and pain share many similarities, they have distinct pathways based on their spinal connections.⁵ Nevertheless, both conditions show a wide overlap of receptors on peripheral nerve endings and activated brain parts.^6,7 Fibromyalgia, the third most common musculoskeletal condition, affects 2% to 3% of the population worldwide and is at least 7 times more common in females.^8,9 Its pathogenesis is not entirely clear but is thought to involve neurogenic inflammation, aberrations in peripheral nerves, and central pain mechanisms. Fibromyalgia is characterized by a plethora of symptoms including chronic widespread pain, autonomic disturbances, persistent fatigue and sleep disturbances, and hyperalgesia, as well as somatic and psychiatric symptoms.¹⁰

Fibromyalgia is accompanied by altered skin features including increased counts of mast cells and excessive degranulation,¹¹ neurogenic inflammation with elevated cytokine expression,¹² disrupted collagen metabolism,¹³ and microcirculation abnormalities.¹⁴ There has been limited research exploring the dermatologic manifestations of fibromyalgia. One retrospective study that included 845 patients with fibromyalgia reported increased occurrence of “neurodermatoses,” including pruritus, neurotic excoriations, prurigo nodules, and lichen simplex chronicus (LSC), among other cutaneous comorbidities.¹⁵ Another small study demonstrated an increased incidence of xerosis and neurotic excoriations in females with fibromyalgia.¹⁶ A paucity of large epidemiologic studies demonstrating the fibromyalgia-pruritus connection may lead to misdiagnosis, misinterpretation, and undertreatment of these patients.

Up to 49% of fibromyalgia patients experience small-fiber neuropathy.¹⁷ Electrophysiologic measurements, quantitative sensory testing, pain-related evoked potentials, and skin biopsies showed that patients with fibromyalgia have compromised small-fiber function, impaired pathways carrying fiber pain signals, and reduced skin innervation and regenerating fibers.^18,19 Accordingly, pruritus that has been reported in fibromyalgia is believed to be of neuropathic origin.¹⁵ Overall, it is suspected that the same mechanism that causes hypersensitivity and pain in fibromyalgia patients also predisposes them to pruritus. Similar systemic treatments (eg, analgesics, antidepressants, anticonvulsants) prescribed for both conditions support this theory.^20-25

Our large cross-sectional study sought to establish the association between fibromyalgia and pruritus as well as related pruritic conditions.

 

Methods

Study Design and Setting—We conducted a cross-­sectional retrospective study using data-mining techniques to access information from the Clalit Health Services (CHS) database. Clalit Health Services is the largest health maintenance organization in Israel. It encompasses an extensive database with continuous real-time input from medical, administrative, and pharmaceutical computerized operating systems, which helps facilitate data collection for epidemiologic studies. A chronic disease register is gathered from these data sources and continuously updated and validated through logistic checks. The current study was approved by the institutional review board of the CHS (approval #0212-17-com2). Informed consent was not required because the data were de-identified and this was a noninterventional observational study.

Study Population and Covariates—Medical records of CHS enrollees were screened for the diagnosis of fibromyalgia, and data on prevalent cases of fibromyalgia were retrieved. The diagnosis of fibromyalgia was based on the documentation of a fibromyalgia-specific diagnostic code registered by a board-certified rheumatologist. A control group of individuals without fibromyalgia was selected through 1:2 matching based on age, sex, and primary care clinic. The control group was randomly selected from the list of CHS members frequency-matched to cases, excluding case patients with fibromyalgia. Age matching was grounded on the exact year of birth (1-year strata).

Other covariates in the analysis included pruritus-related skin disorders, including prurigo nodularis, neurotic excoriations, and LSC. There were 3 socioeconomic status categories according to patients' poverty index: low, intermediate, and high.²⁶

Statistical Analysis—The distribution of sociodemographic and clinical features was compared between patients with fibromyalgia and controls using the χ² test for sex and socioeconomic status and the t test for age. Conditional logistic regression then was used to calculate adjusted odds ratio (OR) and 95% CI to compare patients with fibromyalgia and controls with respect to the presence of pruritic comorbidities. All statistical analyses were performed using SPSS software (version 26). P<.05 was considered statistically significant in all tests.

Results

Our study population comprised 4971 patients with fibromyalgia and 9896 age- and sex-matched controls. Proportional to the reported female predominance among patients with fibromyalgia,²⁷ 4479 (90.1%) patients with fibromyalgia were females and a similar proportion was documented among controls (P=.99). There was a slightly higher proportion of unmarried patients among those with fibromyalgia compared with controls (41.9% vs 39.4%; P=.004). Socioeconomic status was matched between patients and controls (P=.99). Descriptive characteristics of the study population are presented in Table 1.

We assessed the presence of pruritus as well as 3 other pruritus-related skin disorders—prurigo nodularis, neurotic excoriations, and LSC—among patients with fibromyalgia and controls. Logistic regression was used to evaluate the independent association between fibromyalgia and pruritus. Table 2 presents the results of multivariate logistic regression models and summarizes the adjusted ORs for pruritic conditions in patients with fibromyalgia and different demographic features across the entire study sample. Fibromyalgia demonstrated strong independent associations with pruritus (OR, 1.8; 95% CI, 1.8-2.4; P<.001), prurigo nodularis (OR, 2.9; 95% CI, 1.1-8.4; P=.038), and LSC (OR, 1.5; 95% CI, 1.1-2.1; P=.01); the association with neurotic excoriations was not significant. Female sex significantly increased the risk for pruritus (OR 1.3; 95% CI, 1.0-1.6; P=.039), while age slightly increased the odds for pruritus (OR, 1.0; 95% CI, 1.0-1.04; P<.001), neurotic excoriations (OR, 1.0; 95% CI, 1.0-1.1; P=.046), and LSC (OR, 1.0; 95% CI, 1.01-1.04; P=.006). Finally, socioeconomic status was inversely correlated with pruritus (OR, 1.1; 95% CI, 1.1-1.5; P=.002).

Frequencies and ORs for the association between fibromyalgia and pruritus with associated pruritic disorders stratified by exclusion of pruritic dermatologic and/or systemic diseases that may induce itch are presented in the eTable. Analyzing the entire study cohort, significant increases were observed in the odds of all 4 pruritic disorders analyzed. The frequency of pruritus was almost double in patients with fibromyalgia compared with controls (11.7% vs 6.0%; OR, 2.1; 95% CI, 1.8-2.3; P<.0001). Prurigo nodularis (0.2% vs 0.1%; OR, 2.9; 95% CI, 1.1-8.4; P=.05), neurotic excoriations (0.6% vs 0.3%; OR, 1.9; 95% CI, 1.1-3.1; P=.018), and LSC (1.3% vs 0.8%; OR, 1.5; 95% CI, 1.1-2.1; P=.01) frequencies were all higher in patients with fibromyalgia than controls. When primary skin disorders that may cause itch (eg, pemphigus vulgaris, Darier disease, dermatitis, eczema, ichthyosis, psoriasis, parapsoriasis, urticaria, xerosis, atopic dermatitis, dermatitis herpetiformis, lichen planus) were excluded, the prevalence of pruritus in patients with fibromyalgia was still 1.97 times greater than in the controls (6.9% vs. 3.5%; OR, 2.0; 95% CI, 1.7-2.4; P<.0001). These results remained unchanged even when excluding pruritic dermatologic disorders as well as systemic diseases associated with pruritus (eg, chronic renal failure, dialysis, hyperthyroidism, ­hyperparathyroidism/­hypoparathyroidism, ­hypothyroidism). Patients with fibromyalgia still displayed a significantly higher prevalence of pruritus compared with the control group (6.6% vs 3.3%; OR, 2.1; 95% CI, 1.7-2.6; P<.0001).

 

Comment

A wide range of skin manifestations have been associated with fibromyalgia, but the exact mechanisms remain unclear. Nevertheless, it is conceivable that autonomic nervous system dysfunction,^28-31 amplified cutaneous opioid receptor activity,³² and an elevated presence of cutaneous mast cells with excessive degranulation may partially explain the frequent occurrence of pruritus and related skin disorders such as neurotic excoriations, prurigo nodularis, and LSC in individuals with fibromyalgia.^15,16 In line with these findings, our study—which was based on data from the largest health maintenance organization in Israel—demonstrated an increased prevalence of pruritus and related pruritic disorders among individuals diagnosed with fibromyalgia.

This cross-sectional study links pruritus with fibromyalgia. Few preliminary epidemiologic studies have shown an increased occurrence of cutaneous manifestations in patients with fibromyalgia. One chart review that looked at skin findings in patients with fibromyalgia revealed 32 distinct cutaneous manifestations, and pruritus was the major concern in 3.3% of 845 patients.¹⁵

A focused cross-sectional study involving only women (66 with fibromyalgia and 79 healthy controls) discovered 14 skin conditions that were more common in those with fibromyalgia. Notably, xerosis and neurotic excoriations were more prevalent compared to the control group.¹⁶

The brain and the skin—both derivatives of the embryonic ectoderm^33,34—are linked by pruritus. Although itch has its dedicated neurons, there is a wide-ranging overlap of brain-activated areas between pain and itch,⁶ and the neural anatomy of pain and itch are closely related in both the peripheral and central nervous systems^35-37; for example, diseases of the central nervous system are accompanied by pruritus in as many as 15% of cases, while postherpetic neuralgia can result in chronic pain, itching, or a combination of both.^38,39 Other instances include notalgia paresthetica and brachioradial pruritus.³⁸ Additionally, there is a noteworthy psychologic impact associated with both itch and pain,^40,41 with both psychosomatic and psychologic factors implicated in chronic pruritus and in fibromyalgia.⁴² Lastly, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are altered in both fibromyalgia and pruritus.^43-45

Tey et al⁴⁵ characterized the itch experienced in fibromyalgia as functional, which is described as pruritus associated with a somatoform disorder. In our study, we found a higher prevalence of pruritus among patients with fibromyalgia, and this association remained significant (P<.05) even when excluding other pruritic skin conditions and systemic diseases that can trigger itching. In addition, our logistic regression analyses revealed independent associations between fibromyalgia and pruritus, prurigo nodularis, and LSC.

According to Twycross et al,⁴⁶ there are 4 clinical categories of itch, which may coexist⁷: pruritoceptive (originating in the skin), neuropathic (originating in pathology located along the afferent pathway), neurogenic (central origin but lacks a neural pathology), and psychogenic.⁴⁷ Skin biopsy findings in patients with fibromyalgia include increased mast cell counts¹¹ and degranulation,⁴⁸ increased expression of δ and κ opioid receptors,³² vasoconstriction within tender points,⁴⁹ and elevated IL-1β, IL-6, or tumor necrosis factor α by reverse transcriptase-polymerase chain reaction.¹² A case recently was presented by Görg et al⁵⁰ involving a female patient with fibromyalgia who had been experiencing chronic pruritus, which the authors attributed to small-fiber neuropathy based on evidence from a skin biopsy indicating a reduced number of intraepidermal nerves and the fact that the itching originated around tender points. Altogether, the observed alterations may work together to make patients with fibromyalgia more susceptible to various skin-related comorbidities in general, especially those related to pruritus. Eventually, it might be the case that several itch categories and related pathomechanisms are involved in the pruritus phenotype of patients with fibromyalgia.

Age-related alterations in nerve fibers, lower immune function, xerosis, polypharmacy, and increased frequency of systemic diseases with age are just a few of the factors that may predispose older individuals to pruritus.^51,52 Indeed, our logistic regression model showed that age was significantly and independently associated with ­pruritus (P<.001), neurotic excoriations (P=.046), and LSC (P=.006). Female sex also was significantly linked with pruritus (P=.039). Intriguingly, high socioeconomic status was significantly associated with the diagnosis of ­pruritus (P=.002), possibly due to easier access to medical care.

There is a considerable overlap between the therapeutic approaches used in pruritus, pruritus-related skin disorders, and fibromyalgia. Antidepressants, anxiolytics, analgesics, and antiepileptics have been used to address both conditions.⁴⁵ The association between these conditions advocates for a multidisciplinary approach in patients with fibromyalgia and potentially supports the rationale for unified therapeutics for both conditions.

 

Conclusion

Our findings indicate an association between fibromyalgia and pruritus as well as associated pruritic skin disorders. Given the convoluted and largely undiscovered mechanisms underlying fibromyalgia, managing patients with this condition may present substantial challenges.⁵³ The data presented here support the implementation of a multidisciplinary treatment approach for patients with fibromyalgia. This approach should focus on managing fibromyalgia pain as well as addressing its concurrent skin-related conditions. It is advisable to consider treatments such as antiepileptics (eg, pregabalin, gabapentin) that specifically target neuropathic disorders in affected patients. These treatments may hold promise for alleviating fibromyalgia-related pain⁵⁴ and mitigating its related cutaneous comorbidities, especially pruritus.

Pruritus, which is defined as an itching sensation that elicits a desire to scratch, is the most common cutaneous condition. Pruritus is considered chronic when it lasts for more than 6 weeks.¹ Etiologies implicated in chronic pruritus include but are not limited to primary skin diseases such as atopic dermatitis, systemic causes, neuropathic disorders, and psychogenic reasons.² In approximately 8% to 35% of patients, the cause of pruritus remains elusive despite intensive investigation.³ The mechanisms of itch are multifaceted and include complex neural pathways.⁴ Although itch and pain share many similarities, they have distinct pathways based on their spinal connections.⁵ Nevertheless, both conditions show a wide overlap of receptors on peripheral nerve endings and activated brain parts.^6,7 Fibromyalgia, the third most common musculoskeletal condition, affects 2% to 3% of the population worldwide and is at least 7 times more common in females.^8,9 Its pathogenesis is not entirely clear but is thought to involve neurogenic inflammation, aberrations in peripheral nerves, and central pain mechanisms. Fibromyalgia is characterized by a plethora of symptoms including chronic widespread pain, autonomic disturbances, persistent fatigue and sleep disturbances, and hyperalgesia, as well as somatic and psychiatric symptoms.¹⁰

Fibromyalgia is accompanied by altered skin features including increased counts of mast cells and excessive degranulation,¹¹ neurogenic inflammation with elevated cytokine expression,¹² disrupted collagen metabolism,¹³ and microcirculation abnormalities.¹⁴ There has been limited research exploring the dermatologic manifestations of fibromyalgia. One retrospective study that included 845 patients with fibromyalgia reported increased occurrence of “neurodermatoses,” including pruritus, neurotic excoriations, prurigo nodules, and lichen simplex chronicus (LSC), among other cutaneous comorbidities.¹⁵ Another small study demonstrated an increased incidence of xerosis and neurotic excoriations in females with fibromyalgia.¹⁶ A paucity of large epidemiologic studies demonstrating the fibromyalgia-pruritus connection may lead to misdiagnosis, misinterpretation, and undertreatment of these patients.

Up to 49% of fibromyalgia patients experience small-fiber neuropathy.¹⁷ Electrophysiologic measurements, quantitative sensory testing, pain-related evoked potentials, and skin biopsies showed that patients with fibromyalgia have compromised small-fiber function, impaired pathways carrying fiber pain signals, and reduced skin innervation and regenerating fibers.^18,19 Accordingly, pruritus that has been reported in fibromyalgia is believed to be of neuropathic origin.¹⁵ Overall, it is suspected that the same mechanism that causes hypersensitivity and pain in fibromyalgia patients also predisposes them to pruritus. Similar systemic treatments (eg, analgesics, antidepressants, anticonvulsants) prescribed for both conditions support this theory.^20-25

Our large cross-sectional study sought to establish the association between fibromyalgia and pruritus as well as related pruritic conditions.

 

Methods

Study Design and Setting—We conducted a cross-­sectional retrospective study using data-mining techniques to access information from the Clalit Health Services (CHS) database. Clalit Health Services is the largest health maintenance organization in Israel. It encompasses an extensive database with continuous real-time input from medical, administrative, and pharmaceutical computerized operating systems, which helps facilitate data collection for epidemiologic studies. A chronic disease register is gathered from these data sources and continuously updated and validated through logistic checks. The current study was approved by the institutional review board of the CHS (approval #0212-17-com2). Informed consent was not required because the data were de-identified and this was a noninterventional observational study.

Study Population and Covariates—Medical records of CHS enrollees were screened for the diagnosis of fibromyalgia, and data on prevalent cases of fibromyalgia were retrieved. The diagnosis of fibromyalgia was based on the documentation of a fibromyalgia-specific diagnostic code registered by a board-certified rheumatologist. A control group of individuals without fibromyalgia was selected through 1:2 matching based on age, sex, and primary care clinic. The control group was randomly selected from the list of CHS members frequency-matched to cases, excluding case patients with fibromyalgia. Age matching was grounded on the exact year of birth (1-year strata).

Other covariates in the analysis included pruritus-related skin disorders, including prurigo nodularis, neurotic excoriations, and LSC. There were 3 socioeconomic status categories according to patients' poverty index: low, intermediate, and high.²⁶

Statistical Analysis—The distribution of sociodemographic and clinical features was compared between patients with fibromyalgia and controls using the χ² test for sex and socioeconomic status and the t test for age. Conditional logistic regression then was used to calculate adjusted odds ratio (OR) and 95% CI to compare patients with fibromyalgia and controls with respect to the presence of pruritic comorbidities. All statistical analyses were performed using SPSS software (version 26). P<.05 was considered statistically significant in all tests.

Results

Our study population comprised 4971 patients with fibromyalgia and 9896 age- and sex-matched controls. Proportional to the reported female predominance among patients with fibromyalgia,²⁷ 4479 (90.1%) patients with fibromyalgia were females and a similar proportion was documented among controls (P=.99). There was a slightly higher proportion of unmarried patients among those with fibromyalgia compared with controls (41.9% vs 39.4%; P=.004). Socioeconomic status was matched between patients and controls (P=.99). Descriptive characteristics of the study population are presented in Table 1.

We assessed the presence of pruritus as well as 3 other pruritus-related skin disorders—prurigo nodularis, neurotic excoriations, and LSC—among patients with fibromyalgia and controls. Logistic regression was used to evaluate the independent association between fibromyalgia and pruritus. Table 2 presents the results of multivariate logistic regression models and summarizes the adjusted ORs for pruritic conditions in patients with fibromyalgia and different demographic features across the entire study sample. Fibromyalgia demonstrated strong independent associations with pruritus (OR, 1.8; 95% CI, 1.8-2.4; P<.001), prurigo nodularis (OR, 2.9; 95% CI, 1.1-8.4; P=.038), and LSC (OR, 1.5; 95% CI, 1.1-2.1; P=.01); the association with neurotic excoriations was not significant. Female sex significantly increased the risk for pruritus (OR 1.3; 95% CI, 1.0-1.6; P=.039), while age slightly increased the odds for pruritus (OR, 1.0; 95% CI, 1.0-1.04; P<.001), neurotic excoriations (OR, 1.0; 95% CI, 1.0-1.1; P=.046), and LSC (OR, 1.0; 95% CI, 1.01-1.04; P=.006). Finally, socioeconomic status was inversely correlated with pruritus (OR, 1.1; 95% CI, 1.1-1.5; P=.002).

Frequencies and ORs for the association between fibromyalgia and pruritus with associated pruritic disorders stratified by exclusion of pruritic dermatologic and/or systemic diseases that may induce itch are presented in the eTable. Analyzing the entire study cohort, significant increases were observed in the odds of all 4 pruritic disorders analyzed. The frequency of pruritus was almost double in patients with fibromyalgia compared with controls (11.7% vs 6.0%; OR, 2.1; 95% CI, 1.8-2.3; P<.0001). Prurigo nodularis (0.2% vs 0.1%; OR, 2.9; 95% CI, 1.1-8.4; P=.05), neurotic excoriations (0.6% vs 0.3%; OR, 1.9; 95% CI, 1.1-3.1; P=.018), and LSC (1.3% vs 0.8%; OR, 1.5; 95% CI, 1.1-2.1; P=.01) frequencies were all higher in patients with fibromyalgia than controls. When primary skin disorders that may cause itch (eg, pemphigus vulgaris, Darier disease, dermatitis, eczema, ichthyosis, psoriasis, parapsoriasis, urticaria, xerosis, atopic dermatitis, dermatitis herpetiformis, lichen planus) were excluded, the prevalence of pruritus in patients with fibromyalgia was still 1.97 times greater than in the controls (6.9% vs. 3.5%; OR, 2.0; 95% CI, 1.7-2.4; P<.0001). These results remained unchanged even when excluding pruritic dermatologic disorders as well as systemic diseases associated with pruritus (eg, chronic renal failure, dialysis, hyperthyroidism, ­hyperparathyroidism/­hypoparathyroidism, ­hypothyroidism). Patients with fibromyalgia still displayed a significantly higher prevalence of pruritus compared with the control group (6.6% vs 3.3%; OR, 2.1; 95% CI, 1.7-2.6; P<.0001).

 

Comment

A wide range of skin manifestations have been associated with fibromyalgia, but the exact mechanisms remain unclear. Nevertheless, it is conceivable that autonomic nervous system dysfunction,^28-31 amplified cutaneous opioid receptor activity,³² and an elevated presence of cutaneous mast cells with excessive degranulation may partially explain the frequent occurrence of pruritus and related skin disorders such as neurotic excoriations, prurigo nodularis, and LSC in individuals with fibromyalgia.^15,16 In line with these findings, our study—which was based on data from the largest health maintenance organization in Israel—demonstrated an increased prevalence of pruritus and related pruritic disorders among individuals diagnosed with fibromyalgia.

This cross-sectional study links pruritus with fibromyalgia. Few preliminary epidemiologic studies have shown an increased occurrence of cutaneous manifestations in patients with fibromyalgia. One chart review that looked at skin findings in patients with fibromyalgia revealed 32 distinct cutaneous manifestations, and pruritus was the major concern in 3.3% of 845 patients.¹⁵

A focused cross-sectional study involving only women (66 with fibromyalgia and 79 healthy controls) discovered 14 skin conditions that were more common in those with fibromyalgia. Notably, xerosis and neurotic excoriations were more prevalent compared to the control group.¹⁶

The brain and the skin—both derivatives of the embryonic ectoderm^33,34—are linked by pruritus. Although itch has its dedicated neurons, there is a wide-ranging overlap of brain-activated areas between pain and itch,⁶ and the neural anatomy of pain and itch are closely related in both the peripheral and central nervous systems^35-37; for example, diseases of the central nervous system are accompanied by pruritus in as many as 15% of cases, while postherpetic neuralgia can result in chronic pain, itching, or a combination of both.^38,39 Other instances include notalgia paresthetica and brachioradial pruritus.³⁸ Additionally, there is a noteworthy psychologic impact associated with both itch and pain,^40,41 with both psychosomatic and psychologic factors implicated in chronic pruritus and in fibromyalgia.⁴² Lastly, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are altered in both fibromyalgia and pruritus.^43-45

Tey et al⁴⁵ characterized the itch experienced in fibromyalgia as functional, which is described as pruritus associated with a somatoform disorder. In our study, we found a higher prevalence of pruritus among patients with fibromyalgia, and this association remained significant (P<.05) even when excluding other pruritic skin conditions and systemic diseases that can trigger itching. In addition, our logistic regression analyses revealed independent associations between fibromyalgia and pruritus, prurigo nodularis, and LSC.

According to Twycross et al,⁴⁶ there are 4 clinical categories of itch, which may coexist⁷: pruritoceptive (originating in the skin), neuropathic (originating in pathology located along the afferent pathway), neurogenic (central origin but lacks a neural pathology), and psychogenic.⁴⁷ Skin biopsy findings in patients with fibromyalgia include increased mast cell counts¹¹ and degranulation,⁴⁸ increased expression of δ and κ opioid receptors,³² vasoconstriction within tender points,⁴⁹ and elevated IL-1β, IL-6, or tumor necrosis factor α by reverse transcriptase-polymerase chain reaction.¹² A case recently was presented by Görg et al⁵⁰ involving a female patient with fibromyalgia who had been experiencing chronic pruritus, which the authors attributed to small-fiber neuropathy based on evidence from a skin biopsy indicating a reduced number of intraepidermal nerves and the fact that the itching originated around tender points. Altogether, the observed alterations may work together to make patients with fibromyalgia more susceptible to various skin-related comorbidities in general, especially those related to pruritus. Eventually, it might be the case that several itch categories and related pathomechanisms are involved in the pruritus phenotype of patients with fibromyalgia.

Age-related alterations in nerve fibers, lower immune function, xerosis, polypharmacy, and increased frequency of systemic diseases with age are just a few of the factors that may predispose older individuals to pruritus.^51,52 Indeed, our logistic regression model showed that age was significantly and independently associated with ­pruritus (P<.001), neurotic excoriations (P=.046), and LSC (P=.006). Female sex also was significantly linked with pruritus (P=.039). Intriguingly, high socioeconomic status was significantly associated with the diagnosis of ­pruritus (P=.002), possibly due to easier access to medical care.

There is a considerable overlap between the therapeutic approaches used in pruritus, pruritus-related skin disorders, and fibromyalgia. Antidepressants, anxiolytics, analgesics, and antiepileptics have been used to address both conditions.⁴⁵ The association between these conditions advocates for a multidisciplinary approach in patients with fibromyalgia and potentially supports the rationale for unified therapeutics for both conditions.

 

Conclusion

Our findings indicate an association between fibromyalgia and pruritus as well as associated pruritic skin disorders. Given the convoluted and largely undiscovered mechanisms underlying fibromyalgia, managing patients with this condition may present substantial challenges.⁵³ The data presented here support the implementation of a multidisciplinary treatment approach for patients with fibromyalgia. This approach should focus on managing fibromyalgia pain as well as addressing its concurrent skin-related conditions. It is advisable to consider treatments such as antiepileptics (eg, pregabalin, gabapentin) that specifically target neuropathic disorders in affected patients. These treatments may hold promise for alleviating fibromyalgia-related pain⁵⁴ and mitigating its related cutaneous comorbidities, especially pruritus.

Pruritus, which is defined as an itching sensation that elicits a desire to scratch, is the most common cutaneous condition. Pruritus is considered chronic when it lasts for more than 6 weeks.¹ Etiologies implicated in chronic pruritus include but are not limited to primary skin diseases such as atopic dermatitis, systemic causes, neuropathic disorders, and psychogenic reasons.² In approximately 8% to 35% of patients, the cause of pruritus remains elusive despite intensive investigation.³ The mechanisms of itch are multifaceted and include complex neural pathways.⁴ Although itch and pain share many similarities, they have distinct pathways based on their spinal connections.⁵ Nevertheless, both conditions show a wide overlap of receptors on peripheral nerve endings and activated brain parts.^6,7 Fibromyalgia, the third most common musculoskeletal condition, affects 2% to 3% of the population worldwide and is at least 7 times more common in females.^8,9 Its pathogenesis is not entirely clear but is thought to involve neurogenic inflammation, aberrations in peripheral nerves, and central pain mechanisms. Fibromyalgia is characterized by a plethora of symptoms including chronic widespread pain, autonomic disturbances, persistent fatigue and sleep disturbances, and hyperalgesia, as well as somatic and psychiatric symptoms.¹⁰

Fibromyalgia is accompanied by altered skin features including increased counts of mast cells and excessive degranulation,¹¹ neurogenic inflammation with elevated cytokine expression,¹² disrupted collagen metabolism,¹³ and microcirculation abnormalities.¹⁴ There has been limited research exploring the dermatologic manifestations of fibromyalgia. One retrospective study that included 845 patients with fibromyalgia reported increased occurrence of “neurodermatoses,” including pruritus, neurotic excoriations, prurigo nodules, and lichen simplex chronicus (LSC), among other cutaneous comorbidities.¹⁵ Another small study demonstrated an increased incidence of xerosis and neurotic excoriations in females with fibromyalgia.¹⁶ A paucity of large epidemiologic studies demonstrating the fibromyalgia-pruritus connection may lead to misdiagnosis, misinterpretation, and undertreatment of these patients.

Up to 49% of fibromyalgia patients experience small-fiber neuropathy.¹⁷ Electrophysiologic measurements, quantitative sensory testing, pain-related evoked potentials, and skin biopsies showed that patients with fibromyalgia have compromised small-fiber function, impaired pathways carrying fiber pain signals, and reduced skin innervation and regenerating fibers.^18,19 Accordingly, pruritus that has been reported in fibromyalgia is believed to be of neuropathic origin.¹⁵ Overall, it is suspected that the same mechanism that causes hypersensitivity and pain in fibromyalgia patients also predisposes them to pruritus. Similar systemic treatments (eg, analgesics, antidepressants, anticonvulsants) prescribed for both conditions support this theory.^20-25

Our large cross-sectional study sought to establish the association between fibromyalgia and pruritus as well as related pruritic conditions.

 

Methods

Study Design and Setting—We conducted a cross-­sectional retrospective study using data-mining techniques to access information from the Clalit Health Services (CHS) database. Clalit Health Services is the largest health maintenance organization in Israel. It encompasses an extensive database with continuous real-time input from medical, administrative, and pharmaceutical computerized operating systems, which helps facilitate data collection for epidemiologic studies. A chronic disease register is gathered from these data sources and continuously updated and validated through logistic checks. The current study was approved by the institutional review board of the CHS (approval #0212-17-com2). Informed consent was not required because the data were de-identified and this was a noninterventional observational study.

Study Population and Covariates—Medical records of CHS enrollees were screened for the diagnosis of fibromyalgia, and data on prevalent cases of fibromyalgia were retrieved. The diagnosis of fibromyalgia was based on the documentation of a fibromyalgia-specific diagnostic code registered by a board-certified rheumatologist. A control group of individuals without fibromyalgia was selected through 1:2 matching based on age, sex, and primary care clinic. The control group was randomly selected from the list of CHS members frequency-matched to cases, excluding case patients with fibromyalgia. Age matching was grounded on the exact year of birth (1-year strata).

Other covariates in the analysis included pruritus-related skin disorders, including prurigo nodularis, neurotic excoriations, and LSC. There were 3 socioeconomic status categories according to patients' poverty index: low, intermediate, and high.²⁶

Statistical Analysis—The distribution of sociodemographic and clinical features was compared between patients with fibromyalgia and controls using the χ² test for sex and socioeconomic status and the t test for age. Conditional logistic regression then was used to calculate adjusted odds ratio (OR) and 95% CI to compare patients with fibromyalgia and controls with respect to the presence of pruritic comorbidities. All statistical analyses were performed using SPSS software (version 26). P<.05 was considered statistically significant in all tests.

Results

Our study population comprised 4971 patients with fibromyalgia and 9896 age- and sex-matched controls. Proportional to the reported female predominance among patients with fibromyalgia,²⁷ 4479 (90.1%) patients with fibromyalgia were females and a similar proportion was documented among controls (P=.99). There was a slightly higher proportion of unmarried patients among those with fibromyalgia compared with controls (41.9% vs 39.4%; P=.004). Socioeconomic status was matched between patients and controls (P=.99). Descriptive characteristics of the study population are presented in Table 1.

We assessed the presence of pruritus as well as 3 other pruritus-related skin disorders—prurigo nodularis, neurotic excoriations, and LSC—among patients with fibromyalgia and controls. Logistic regression was used to evaluate the independent association between fibromyalgia and pruritus. Table 2 presents the results of multivariate logistic regression models and summarizes the adjusted ORs for pruritic conditions in patients with fibromyalgia and different demographic features across the entire study sample. Fibromyalgia demonstrated strong independent associations with pruritus (OR, 1.8; 95% CI, 1.8-2.4; P<.001), prurigo nodularis (OR, 2.9; 95% CI, 1.1-8.4; P=.038), and LSC (OR, 1.5; 95% CI, 1.1-2.1; P=.01); the association with neurotic excoriations was not significant. Female sex significantly increased the risk for pruritus (OR 1.3; 95% CI, 1.0-1.6; P=.039), while age slightly increased the odds for pruritus (OR, 1.0; 95% CI, 1.0-1.04; P<.001), neurotic excoriations (OR, 1.0; 95% CI, 1.0-1.1; P=.046), and LSC (OR, 1.0; 95% CI, 1.01-1.04; P=.006). Finally, socioeconomic status was inversely correlated with pruritus (OR, 1.1; 95% CI, 1.1-1.5; P=.002).

Frequencies and ORs for the association between fibromyalgia and pruritus with associated pruritic disorders stratified by exclusion of pruritic dermatologic and/or systemic diseases that may induce itch are presented in the eTable. Analyzing the entire study cohort, significant increases were observed in the odds of all 4 pruritic disorders analyzed. The frequency of pruritus was almost double in patients with fibromyalgia compared with controls (11.7% vs 6.0%; OR, 2.1; 95% CI, 1.8-2.3; P<.0001). Prurigo nodularis (0.2% vs 0.1%; OR, 2.9; 95% CI, 1.1-8.4; P=.05), neurotic excoriations (0.6% vs 0.3%; OR, 1.9; 95% CI, 1.1-3.1; P=.018), and LSC (1.3% vs 0.8%; OR, 1.5; 95% CI, 1.1-2.1; P=.01) frequencies were all higher in patients with fibromyalgia than controls. When primary skin disorders that may cause itch (eg, pemphigus vulgaris, Darier disease, dermatitis, eczema, ichthyosis, psoriasis, parapsoriasis, urticaria, xerosis, atopic dermatitis, dermatitis herpetiformis, lichen planus) were excluded, the prevalence of pruritus in patients with fibromyalgia was still 1.97 times greater than in the controls (6.9% vs. 3.5%; OR, 2.0; 95% CI, 1.7-2.4; P<.0001). These results remained unchanged even when excluding pruritic dermatologic disorders as well as systemic diseases associated with pruritus (eg, chronic renal failure, dialysis, hyperthyroidism, ­hyperparathyroidism/­hypoparathyroidism, ­hypothyroidism). Patients with fibromyalgia still displayed a significantly higher prevalence of pruritus compared with the control group (6.6% vs 3.3%; OR, 2.1; 95% CI, 1.7-2.6; P<.0001).

 

Comment

A wide range of skin manifestations have been associated with fibromyalgia, but the exact mechanisms remain unclear. Nevertheless, it is conceivable that autonomic nervous system dysfunction,^28-31 amplified cutaneous opioid receptor activity,³² and an elevated presence of cutaneous mast cells with excessive degranulation may partially explain the frequent occurrence of pruritus and related skin disorders such as neurotic excoriations, prurigo nodularis, and LSC in individuals with fibromyalgia.^15,16 In line with these findings, our study—which was based on data from the largest health maintenance organization in Israel—demonstrated an increased prevalence of pruritus and related pruritic disorders among individuals diagnosed with fibromyalgia.

This cross-sectional study links pruritus with fibromyalgia. Few preliminary epidemiologic studies have shown an increased occurrence of cutaneous manifestations in patients with fibromyalgia. One chart review that looked at skin findings in patients with fibromyalgia revealed 32 distinct cutaneous manifestations, and pruritus was the major concern in 3.3% of 845 patients.¹⁵

A focused cross-sectional study involving only women (66 with fibromyalgia and 79 healthy controls) discovered 14 skin conditions that were more common in those with fibromyalgia. Notably, xerosis and neurotic excoriations were more prevalent compared to the control group.¹⁶

The brain and the skin—both derivatives of the embryonic ectoderm^33,34—are linked by pruritus. Although itch has its dedicated neurons, there is a wide-ranging overlap of brain-activated areas between pain and itch,⁶ and the neural anatomy of pain and itch are closely related in both the peripheral and central nervous systems^35-37; for example, diseases of the central nervous system are accompanied by pruritus in as many as 15% of cases, while postherpetic neuralgia can result in chronic pain, itching, or a combination of both.^38,39 Other instances include notalgia paresthetica and brachioradial pruritus.³⁸ Additionally, there is a noteworthy psychologic impact associated with both itch and pain,^40,41 with both psychosomatic and psychologic factors implicated in chronic pruritus and in fibromyalgia.⁴² Lastly, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are altered in both fibromyalgia and pruritus.^43-45

Tey et al⁴⁵ characterized the itch experienced in fibromyalgia as functional, which is described as pruritus associated with a somatoform disorder. In our study, we found a higher prevalence of pruritus among patients with fibromyalgia, and this association remained significant (P<.05) even when excluding other pruritic skin conditions and systemic diseases that can trigger itching. In addition, our logistic regression analyses revealed independent associations between fibromyalgia and pruritus, prurigo nodularis, and LSC.

According to Twycross et al,⁴⁶ there are 4 clinical categories of itch, which may coexist⁷: pruritoceptive (originating in the skin), neuropathic (originating in pathology located along the afferent pathway), neurogenic (central origin but lacks a neural pathology), and psychogenic.⁴⁷ Skin biopsy findings in patients with fibromyalgia include increased mast cell counts¹¹ and degranulation,⁴⁸ increased expression of δ and κ opioid receptors,³² vasoconstriction within tender points,⁴⁹ and elevated IL-1β, IL-6, or tumor necrosis factor α by reverse transcriptase-polymerase chain reaction.¹² A case recently was presented by Görg et al⁵⁰ involving a female patient with fibromyalgia who had been experiencing chronic pruritus, which the authors attributed to small-fiber neuropathy based on evidence from a skin biopsy indicating a reduced number of intraepidermal nerves and the fact that the itching originated around tender points. Altogether, the observed alterations may work together to make patients with fibromyalgia more susceptible to various skin-related comorbidities in general, especially those related to pruritus. Eventually, it might be the case that several itch categories and related pathomechanisms are involved in the pruritus phenotype of patients with fibromyalgia.

Age-related alterations in nerve fibers, lower immune function, xerosis, polypharmacy, and increased frequency of systemic diseases with age are just a few of the factors that may predispose older individuals to pruritus.^51,52 Indeed, our logistic regression model showed that age was significantly and independently associated with ­pruritus (P<.001), neurotic excoriations (P=.046), and LSC (P=.006). Female sex also was significantly linked with pruritus (P=.039). Intriguingly, high socioeconomic status was significantly associated with the diagnosis of ­pruritus (P=.002), possibly due to easier access to medical care.

There is a considerable overlap between the therapeutic approaches used in pruritus, pruritus-related skin disorders, and fibromyalgia. Antidepressants, anxiolytics, analgesics, and antiepileptics have been used to address both conditions.⁴⁵ The association between these conditions advocates for a multidisciplinary approach in patients with fibromyalgia and potentially supports the rationale for unified therapeutics for both conditions.

 

Conclusion

Our findings indicate an association between fibromyalgia and pruritus as well as associated pruritic skin disorders. Given the convoluted and largely undiscovered mechanisms underlying fibromyalgia, managing patients with this condition may present substantial challenges.⁵³ The data presented here support the implementation of a multidisciplinary treatment approach for patients with fibromyalgia. This approach should focus on managing fibromyalgia pain as well as addressing its concurrent skin-related conditions. It is advisable to consider treatments such as antiepileptics (eg, pregabalin, gabapentin) that specifically target neuropathic disorders in affected patients. These treatments may hold promise for alleviating fibromyalgia-related pain⁵⁴ and mitigating its related cutaneous comorbidities, especially pruritus.

To the Editor:

Generalized bullous fixed drug eruption (GBFDE) is a rare subtype of fixed drug eruption (FDE) that manifests as widespread blisters and erosions following exposure to a causative drug.¹ Diagnostic criteria include involvement of at least 3 to 6 anatomic sites—head and neck, anterior trunk, posterior trunk, upper extremities, lower extremities, or genitalia—and more than 10% of the body surface area. It can be challenging to differentiate GBFDE from severe drug rashes such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) due to extensive body surface area involvement of blisters and erosions. Specific features distinguishing GBFDE from SJS/TEN include primary lesions consisting of larger erythematous to dusky, circular plaques that progress to bullae and coalesce into widespread erosions; history of FDE; lack of severe mucosal involvement; and better overall prognosis.² Treatment typically involves discontinuation of the culprit medication and supportive care; evidence for systemic therapies is not well established.

Our study aimed to characterize the clinical and demographic features of GBFDE in our institution to highlight potential key differences between this diagnosis and SJS/TEN. An electronic medical record search was performed to identify patients who were clinically diagnosed with GBFDE at New York-Presbyterian/Weill Cornell Medical Center (New York, New York) in both outpatient and inpatient settings from January 2015 to December 2022. This retrospective study was approved by the Weill Cornell Medicine institutional review board (#22-05024777).

Ten patients were identified and included in the analysis (eTable). The mean age of the patients was 56 years (range, 39–76 years). Seven (70%) patients had skin of color (non-White) and 6 (60%) were female. The mean body mass index was 35 (range, 20–57), and 7 (70%) patients were clinically obese (body mass index >30). Only 2 (20%) patients had a history of a documented drug eruption (hives and erythema multiforme), and no patients had a history of FDE. Erythematous dusky patches followed by rapid development of blisters were noted within 3 days of drug initiation in 40% (4/10) and within 5 days in 80% (8/10) of patients. Antibiotics were identified as likely inciting agents in 8 (80%) patients. Biopsies were obtained in 3 (30%) patients and all 3 demonstrated cytotoxic CD8⁺ interface dermatitis with marked epithelial necrosis, neutrophilia, eosinophilia, and melanophage accumulation. Fever was present at initial presentation in only 4 (40%) patients, and only 1 (10%) patient had oral mucosal involvement. All 10 patients had intertriginous involvement (axillae, 90% [9/10]; gluteal cleft, 80% [8/10]; groin, 80% [8/10]; inframammary folds, 20% [2/10]), and there was considerable flank involvement in 9 (90%) patients. All 10 patients had initial erythematous to dusky, circular patches on the trunk and proximal extremities that then denuded most dramatically in the intertriginous areas (Figure). Six (60%) patients received systemic therapy, including 5 patients treated with a single dose of etanercept 50 mg. In patients with continued progression, 1 or 2 additional doses of etanercept 50 mg were administered at 48- to 72-hour intervals until blistering halted. Treatment with etanercept resulted in clinical improvement in all 5 patients, and there were no identifiable adverse events. The mean hospital stay was 19.7 days (range, 1–63 days).

This study highlights notable demographic and clinical features of GBFDE that have not been widely described in the literature. Large erythematous and dusky patches with broad zones of blistering with particular localization to the neck, intertriginous areas, and flanks typically are not described in SJS/TEN and may be helpful in distinguishing these conditions from GBFDE. Mild or complete lack of mucosal and facial involvement as well as more rapid time from drug initiation to rash (as rapid as 1 day) were key factors that aided in distinguishing GBFDE from SJS/TEN in our patients. Although a history of FDE is considered a key characteristic in the diagnosis of GBFDE, none of our patients had a known history of FDE, suggesting GBFDE may be the initial manifestation of FDE in some patients. Histopathology showed similar findings consistent with FDE in the 3 patients in whom a biopsy was performed. The remaining patients were diagnosed clinically based on the presence of distinctive, perfectly circular, dusky plaques present at the periphery of larger denuded areas, which are characteristic of GBFDE. Lower levels of serum granulysin³ have been shown to help distinguish GBFDE from SJS/TEN, but this test is not readily available with time-sensitive results at most institutions, and exact diagnostic ranges for GBFDE vs SJS/TEN are not yet known.

Our study was limited by a small number of patients at a single institution. Another limitation was the retrospective design.

Interestingly, a high proportion of our patients were non-White and clinically obese, which are factors that should be considered for future research. Sixty percent (6/10) of the patients in our study were Black, which is a notable difference from our hospital’s general admission demographics with Black individuals constituting 12% of patients.⁴ Our study also highlighted the utility of etanercept, which has reported mortality benefits and decreased time to re-epithelialization in other severe blistering cutaneous drug reactions including SJS/TEN,⁵ as a potential therapeutic option in GBFDE.

It is imperative that clinicians recognize the differences between GBFDE and SJS/TEN, as correct diagnosis is crucial for identifying the most likely causative drug as well as providing accurate prognostic information and may have future therapeutic implications as we further understand the immunologic profiles of these severe blistering drug reactions.

To the Editor:

Generalized bullous fixed drug eruption (GBFDE) is a rare subtype of fixed drug eruption (FDE) that manifests as widespread blisters and erosions following exposure to a causative drug.¹ Diagnostic criteria include involvement of at least 3 to 6 anatomic sites—head and neck, anterior trunk, posterior trunk, upper extremities, lower extremities, or genitalia—and more than 10% of the body surface area. It can be challenging to differentiate GBFDE from severe drug rashes such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) due to extensive body surface area involvement of blisters and erosions. Specific features distinguishing GBFDE from SJS/TEN include primary lesions consisting of larger erythematous to dusky, circular plaques that progress to bullae and coalesce into widespread erosions; history of FDE; lack of severe mucosal involvement; and better overall prognosis.² Treatment typically involves discontinuation of the culprit medication and supportive care; evidence for systemic therapies is not well established.

Our study aimed to characterize the clinical and demographic features of GBFDE in our institution to highlight potential key differences between this diagnosis and SJS/TEN. An electronic medical record search was performed to identify patients who were clinically diagnosed with GBFDE at New York-Presbyterian/Weill Cornell Medical Center (New York, New York) in both outpatient and inpatient settings from January 2015 to December 2022. This retrospective study was approved by the Weill Cornell Medicine institutional review board (#22-05024777).

Ten patients were identified and included in the analysis (eTable). The mean age of the patients was 56 years (range, 39–76 years). Seven (70%) patients had skin of color (non-White) and 6 (60%) were female. The mean body mass index was 35 (range, 20–57), and 7 (70%) patients were clinically obese (body mass index >30). Only 2 (20%) patients had a history of a documented drug eruption (hives and erythema multiforme), and no patients had a history of FDE. Erythematous dusky patches followed by rapid development of blisters were noted within 3 days of drug initiation in 40% (4/10) and within 5 days in 80% (8/10) of patients. Antibiotics were identified as likely inciting agents in 8 (80%) patients. Biopsies were obtained in 3 (30%) patients and all 3 demonstrated cytotoxic CD8⁺ interface dermatitis with marked epithelial necrosis, neutrophilia, eosinophilia, and melanophage accumulation. Fever was present at initial presentation in only 4 (40%) patients, and only 1 (10%) patient had oral mucosal involvement. All 10 patients had intertriginous involvement (axillae, 90% [9/10]; gluteal cleft, 80% [8/10]; groin, 80% [8/10]; inframammary folds, 20% [2/10]), and there was considerable flank involvement in 9 (90%) patients. All 10 patients had initial erythematous to dusky, circular patches on the trunk and proximal extremities that then denuded most dramatically in the intertriginous areas (Figure). Six (60%) patients received systemic therapy, including 5 patients treated with a single dose of etanercept 50 mg. In patients with continued progression, 1 or 2 additional doses of etanercept 50 mg were administered at 48- to 72-hour intervals until blistering halted. Treatment with etanercept resulted in clinical improvement in all 5 patients, and there were no identifiable adverse events. The mean hospital stay was 19.7 days (range, 1–63 days).

This study highlights notable demographic and clinical features of GBFDE that have not been widely described in the literature. Large erythematous and dusky patches with broad zones of blistering with particular localization to the neck, intertriginous areas, and flanks typically are not described in SJS/TEN and may be helpful in distinguishing these conditions from GBFDE. Mild or complete lack of mucosal and facial involvement as well as more rapid time from drug initiation to rash (as rapid as 1 day) were key factors that aided in distinguishing GBFDE from SJS/TEN in our patients. Although a history of FDE is considered a key characteristic in the diagnosis of GBFDE, none of our patients had a known history of FDE, suggesting GBFDE may be the initial manifestation of FDE in some patients. Histopathology showed similar findings consistent with FDE in the 3 patients in whom a biopsy was performed. The remaining patients were diagnosed clinically based on the presence of distinctive, perfectly circular, dusky plaques present at the periphery of larger denuded areas, which are characteristic of GBFDE. Lower levels of serum granulysin³ have been shown to help distinguish GBFDE from SJS/TEN, but this test is not readily available with time-sensitive results at most institutions, and exact diagnostic ranges for GBFDE vs SJS/TEN are not yet known.

Our study was limited by a small number of patients at a single institution. Another limitation was the retrospective design.

Interestingly, a high proportion of our patients were non-White and clinically obese, which are factors that should be considered for future research. Sixty percent (6/10) of the patients in our study were Black, which is a notable difference from our hospital’s general admission demographics with Black individuals constituting 12% of patients.⁴ Our study also highlighted the utility of etanercept, which has reported mortality benefits and decreased time to re-epithelialization in other severe blistering cutaneous drug reactions including SJS/TEN,⁵ as a potential therapeutic option in GBFDE.

It is imperative that clinicians recognize the differences between GBFDE and SJS/TEN, as correct diagnosis is crucial for identifying the most likely causative drug as well as providing accurate prognostic information and may have future therapeutic implications as we further understand the immunologic profiles of these severe blistering drug reactions.

To the Editor:

Generalized bullous fixed drug eruption (GBFDE) is a rare subtype of fixed drug eruption (FDE) that manifests as widespread blisters and erosions following exposure to a causative drug.¹ Diagnostic criteria include involvement of at least 3 to 6 anatomic sites—head and neck, anterior trunk, posterior trunk, upper extremities, lower extremities, or genitalia—and more than 10% of the body surface area. It can be challenging to differentiate GBFDE from severe drug rashes such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) due to extensive body surface area involvement of blisters and erosions. Specific features distinguishing GBFDE from SJS/TEN include primary lesions consisting of larger erythematous to dusky, circular plaques that progress to bullae and coalesce into widespread erosions; history of FDE; lack of severe mucosal involvement; and better overall prognosis.² Treatment typically involves discontinuation of the culprit medication and supportive care; evidence for systemic therapies is not well established.

Our study aimed to characterize the clinical and demographic features of GBFDE in our institution to highlight potential key differences between this diagnosis and SJS/TEN. An electronic medical record search was performed to identify patients who were clinically diagnosed with GBFDE at New York-Presbyterian/Weill Cornell Medical Center (New York, New York) in both outpatient and inpatient settings from January 2015 to December 2022. This retrospective study was approved by the Weill Cornell Medicine institutional review board (#22-05024777).

Ten patients were identified and included in the analysis (eTable). The mean age of the patients was 56 years (range, 39–76 years). Seven (70%) patients had skin of color (non-White) and 6 (60%) were female. The mean body mass index was 35 (range, 20–57), and 7 (70%) patients were clinically obese (body mass index >30). Only 2 (20%) patients had a history of a documented drug eruption (hives and erythema multiforme), and no patients had a history of FDE. Erythematous dusky patches followed by rapid development of blisters were noted within 3 days of drug initiation in 40% (4/10) and within 5 days in 80% (8/10) of patients. Antibiotics were identified as likely inciting agents in 8 (80%) patients. Biopsies were obtained in 3 (30%) patients and all 3 demonstrated cytotoxic CD8⁺ interface dermatitis with marked epithelial necrosis, neutrophilia, eosinophilia, and melanophage accumulation. Fever was present at initial presentation in only 4 (40%) patients, and only 1 (10%) patient had oral mucosal involvement. All 10 patients had intertriginous involvement (axillae, 90% [9/10]; gluteal cleft, 80% [8/10]; groin, 80% [8/10]; inframammary folds, 20% [2/10]), and there was considerable flank involvement in 9 (90%) patients. All 10 patients had initial erythematous to dusky, circular patches on the trunk and proximal extremities that then denuded most dramatically in the intertriginous areas (Figure). Six (60%) patients received systemic therapy, including 5 patients treated with a single dose of etanercept 50 mg. In patients with continued progression, 1 or 2 additional doses of etanercept 50 mg were administered at 48- to 72-hour intervals until blistering halted. Treatment with etanercept resulted in clinical improvement in all 5 patients, and there were no identifiable adverse events. The mean hospital stay was 19.7 days (range, 1–63 days).

This study highlights notable demographic and clinical features of GBFDE that have not been widely described in the literature. Large erythematous and dusky patches with broad zones of blistering with particular localization to the neck, intertriginous areas, and flanks typically are not described in SJS/TEN and may be helpful in distinguishing these conditions from GBFDE. Mild or complete lack of mucosal and facial involvement as well as more rapid time from drug initiation to rash (as rapid as 1 day) were key factors that aided in distinguishing GBFDE from SJS/TEN in our patients. Although a history of FDE is considered a key characteristic in the diagnosis of GBFDE, none of our patients had a known history of FDE, suggesting GBFDE may be the initial manifestation of FDE in some patients. Histopathology showed similar findings consistent with FDE in the 3 patients in whom a biopsy was performed. The remaining patients were diagnosed clinically based on the presence of distinctive, perfectly circular, dusky plaques present at the periphery of larger denuded areas, which are characteristic of GBFDE. Lower levels of serum granulysin³ have been shown to help distinguish GBFDE from SJS/TEN, but this test is not readily available with time-sensitive results at most institutions, and exact diagnostic ranges for GBFDE vs SJS/TEN are not yet known.

Our study was limited by a small number of patients at a single institution. Another limitation was the retrospective design.

Interestingly, a high proportion of our patients were non-White and clinically obese, which are factors that should be considered for future research. Sixty percent (6/10) of the patients in our study were Black, which is a notable difference from our hospital’s general admission demographics with Black individuals constituting 12% of patients.⁴ Our study also highlighted the utility of etanercept, which has reported mortality benefits and decreased time to re-epithelialization in other severe blistering cutaneous drug reactions including SJS/TEN,⁵ as a potential therapeutic option in GBFDE.

It is imperative that clinicians recognize the differences between GBFDE and SJS/TEN, as correct diagnosis is crucial for identifying the most likely causative drug as well as providing accurate prognostic information and may have future therapeutic implications as we further understand the immunologic profiles of these severe blistering drug reactions.