Dear Editor, Hidradenitis suppurativa (HS) is a debilitating inflammatory disease that is understudied, underfunded and notable for a mean diagnostic delay of approximately 7 years.1,2 We aimed to characterize annual HS-related publications across medical fields of study relating to HS care in order to measure the extent of awareness, education and ongoing research in this area.
HS publications from 1 January 2000 to 29 February 2020 were identified in Embase using the following search terms: ‘hidradenitis suppurativa’, ‘acne inversa’, ‘apocrine acne’, ‘Foxden disease’, ‘hidradenitis axillaris’, ‘pyodermia significa fistulans’, ‘Velpeau’s disease’ and ‘Verneuil’s disease’. Duplicate publications, corrections, commentaries, quizzes, meeting proceedings, publications unrelated to HS, and non-English-language publications were excluded. Each included publication was categorized by medical field of study, topic and article type by three investigators. Medical field of study was determined based on each journal’s classification of their own content. Publications were categorized as original if they reported new research or a previously unreported case. Publications reporting three cases or fewer were categorized as case reports. The distribution of annual publications was examined by year, specialty, topic and article type. Descriptive statistics are presented below.
We identified 3610 HS publications across journals in 33 medical subspecialties and excluded 735 publications. Of the excluded publications, 38·6% (284 of 735) were an excluded publication type, 28·3% (208 of 735) were not predominantly about HS, 19·3% (142 of 735) were duplicate publications and 13·7% (101 of 735) were non-English-language articles. More than half of these articles (50·9%, 1464 of 2875) were published between 1 January 2017 and 29 February 2020, with more publications in 2019 (n = 628) than between 2000 and 2011 overall (n = 542). The vast majority of all publications were in dermatology journals (73·3%, 2106 of 2875), followed by general medicine (4·9%, 142 of 2875) and plastic surgery (3·8%, 108 of 2875) journals. Total publications since 2000 in journals for frontline specialties were sparse [general medicine 4·9% (142 of 2875), obstetrics and gynaecology 1·0% (28 of 2875), family medicine 0·4% (12 of 2875), paediatrics 0·2% (six of 2875) and emergency medicine 0·1% (four of 2875)]. While annual publications overall increased in dermatology, general medicine, plastic surgery, gastroenterology and general surgery from 2013 to 2019, zero to three HS publications were published annually in obstetrics and gynaecology, family medicine, paediatrics and emergency medicine. Only 6·7% (192 of 2875) of total HS publications from 2000 to 2020 were published in frontline specialties. Overall, 73% (2106 of 2875) of publications reported original research, ranging from 52% in 2007 to 83% in 2018, with the majority published in dermatology journals (75·3%, 1586 of 2106). However, over one-quarter (27·5%, 579 of 2106) of the original research publications were case reports, ranging from 16·3% in 2017 to 47·2% in 2006. Therapy (36·9%), comorbidities (18·5%), clinical course (15·4%) and pathophysiology (15·4%) comprised the most commonly covered topics overall (Table 1).
Table 1.
Hidradenitis suppurativa publication topics across medical fields of study
| Total across all specialtiesa (n = 2875) |
Dermatology (n = 2106) |
General medicine (n = 142) |
Plastic surgery (n = 108) |
Gastroenterology (n = 81) |
Basic science (n = 72) |
General surgery (n = 69) |
Pharmacology (n = 56) |
|
|---|---|---|---|---|---|---|---|---|
| Therapy | 1060 (36·9) | 728 (34·6) | 36 (25·4) | 87 (80·6) | 31 (38) | 20 (28) | 42 (61) | 43 (77) |
| Comorbidities | 531 (18·5) | 392 (18·6) | 36 (25·4) | 7 (6·5) | 31 (38) | 3 (4) | 8 (12) | 2 (4) |
| Clinical course | 444 (15·4) | 297 (14·1) | 38 (26·8) | 10 (9·3) | 13 (16) | 7 (10) | 15 (22) | 2 (4) |
| Pathophysiology | 444 (15·4) | 343 (16·3) | 18 (12·7) | 2 (1·9) | 2 (3) | 39 (54) | 0 (0) | 6 (11) |
| Epidemiology | 119 (4·1) | 107 (5·1) | 4 (2·8) | 0 (0) | 2 (3) | 0 (0) | 1 (1) | 0 (0) |
| Quality of life | 110 (3·8) | 103 (4·9) | 2 (1·4) | 0 (0) | 0 (0) | 0 (0) | 1 (1) | 0 (0) |
| Outcome measures | 78 (2·7) | 68 (3·2) | 2 (1·4) | 1 (0·9) | 0 (0) | 2 (3) | 0 (0) | 0 (0) |
| Health resource utilization | 44 (1·5) | 33 (1·6) | 4 (2·8) | 1 (0·9) | 0 (0) | 0 (0) | 0 (0) | 2 (4) |
| Otherb | 45 (1·6) | 35 (1·7) | 2 (1·4) | 0 (0) | 2 (3) | 0 (0) | 2 (3) | 1 (2) |
Includes the top seven most published fields of study, in addition to other fields including allergy and immunology (n = 13), anaesthesiology (n = 3), emergency medicine (n = 4), embryology (n = 1), endocrinology (n = 5), epidemiology (n = 2), family medicine (n = 12), genetics (n = 6), health economics (n = 17), infectious disease (n = 10), nephrology (n = 4), neurology (n = 2), nursing (n = 4), nutrition (n = 4), obstetrics and gynaecology (n = 28), oncology (n = 8), ophthalmology (n = 6), pathology (n = 10), paediatrics (n = 6), physical medicine and rehabilitation (n = 2), psychiatry (n = 1), pulmonology (n = 2), radiology (n = 23), rheumatology (n = 50), transplant (n = 5) and urology (n = 13).
Other category includes paediatric hidradenitis suppurativa and hidradenitis suppurativa in pregnancy.
Data are provided as n (%).
We report a steady increase in total annual HS publications over the last 8 years, with over half of all HS publications from 1 January 2000 to 29 February 2020 published from 2017 onwards, and the majority published in dermatology journals. Over this period, annual HS publications in frontline specialties have been few and stagnant in number. More than one-quarter of all HS publications do not report original findings. Therapy was the most common article topic, and publications reporting HS clinical course and mechanisms were half as common.
Although the recent increase in annual HS publications suggests increased engagement from the medical community, our study highlights specific gaps in the literature that may explain recently identified barriers in HS care – specifically, poor awareness of and knowledge about HS by healthcare providers.3 Publications in frontline specialties continue to be scarce, suggesting that decreased HS awareness and education in these fields may contribute to delayed diagnosis and treatment.4 Our findings also support the need for increased research in areas including HS pathophysiology and clinical course to lay the groundwork for development of prognostic indicators, biomarkers and more effective therapies.
Our study is limited by its retrospective design and focus on English-language publications. Despite these limitations, our findings help to explain existing barriers to advancements in care and provide important guidance for improving HS awareness, education and research efforts.
Acknowledgments
Funding sources: this research was supported by the Dermatology Foundation and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (K23 AR074531).
Conflicts of interest: H.B.N. has received grant funding from AbbVie, consulting fees from 23andme, and is a board member of the Hidradenitis Suppurativa Foundation.
References
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