SHORT COMMUNICATION
Amanda T. BROSBØL1*, Dorra BOUAZZI1,2, Gregor B.E. JEMEC1-3 and Ditte M.L. SAUNTE1-3
1Department of Dermatology, Zealand University Hospital, Roskilde, Denmark, 2Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark, and 3Dermatology Clinic, Landssjukrahusid, Tórshavn, Faroe Islands. *E-mail: amandatbrosboel@gmail.com
Citation: Acta Derm Venereol 2024; 104: adv41138. DOI: https://doi.org/10.2340/actadv.v104.41138.
Copyright: 2024 © The Author(s). Published by MJS Publishing, on behalf of the Society for Publication of Acta Dermato-Venereologica. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/).
Submitted: Jul 7, 2024. Accepted: Jul 29, 2024. Published: Aug 28, 2024
Competing interests and funding: DB: UCB Nordic paid for EADV Congress 2022 participation. GBEJ has received honoraria from AbbVie, Chemocentryx, Coloplast, Incyte, Inflarx, Novartis, Pierre Fabre, and UCB for participation on advisory boards, and grants from Abbvie, Astra-Zeneca, Inflarx, Janssen-Cilag, Leo Pharma, Novartis, Regeneron, and Sanofi for participation as an investigator, and received speaker honoraria from AbbVie, Boehringer-Ingelheim, Galderma, and MSD. He has also received unrestricted departmental grants from Abbvie, Leo Pharma, and Novartis. DMLS reports personal fees from UCB, AbbVie, Janssen, Jamjoom Pharma, and Sanofi, grants and personal fees from Abbvie, Leo Pharma, Pfizer, and Novartis outside the submitted work.
Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease (1). Patients develop painful suppurating nodules and/or abscesses, always located in the axillary, inguinal, peri-genital, and perineal regions. The disease can progress and lead to scarring and the formation of tunnels (2). Studies have shown a correlation with the severity of HS and obesity and smoking (3). The diagnostic delay in HS diagnosis is 7.2 years globally (4). The diagnostic delay results in delayed treatment initiation.
The worldwide prevalence of HS has been estimated to be 0.0003–4% (4). The prevalence of HS in the Faroe Islands is unknown. This study was undertaken to estimate the population-based prevalence of HS, and to describe the epidemiology of HS patients in the Faroe Islands.
The study was conducted as a retrospective registry-based study including HS patients registered in the Telemedicine patient records system (Danish Telemedicine, Copenhagen, Denmark) from the dermatological outpatient clinic, Landssjukrahusid, Torshavn, Faroe Islands during a period from 2007–2022. Patients registered in the Telemedicine system are referred from general practitioners. We included demographic information, HS-specific data, and treatment-related data. In cases where no Hurley stage was recorded and photos of the lesions were available, the Hurley stage was identified by (DB & DMS) using the Hurley classification. The predefined data were extracted into an Excel spreadsheet by two investigators (AB & DB) separately for quality control. The prevalence of HS in the Faroe Islands was calculated based on a total population of 48,865 persons (data from 2020) (5).
A total of 45 individuals were diagnosed with HS. The prevalence of HS in the Faroe Islands is therefore 0.9% (45/48.865; CI 0.69–1.2). The majority (78%) of the HS patients were women. The median age at first contact was 33 years (IQR 25–46). Sixteen (36%) individuals were currently smoking. The mean ± standard deviation BMI of the HS population was 34.1 ± 4.48. Areas of the skin affected indicated the axilla and the groin as the most common areas. Most patients (84%) were affected in multiple anatomical areas. Twenty-three (51%) medical records had data regarding a diagnostic delay, which was calculated to be a median of 10 years (IQR 5–25).
Twenty-one (47%) of the patients had received treatment before diagnosis. The most common past treatment for HS was systemic antibiotic therapy. All patients, except one, had been treated with a topical treatment after diagnosis. The majority (78%) had received systemic treatment after diagnosis, with systemic antibiotics being the most common. Tetracyclines (doxycycline and tetracycline) represented 60% of the patients being treated with antibiotics. See Table I for more information.
| Patients, n (%) | Drug | Patients, n (%)* | |
| Treatment before diagnosis | |||
| Yes No |
21 (47) 24 (53) |
Antibiotics Tetracycline (systemic) Antibiotics (not specified) Fucidin (topical) Clindamycin (systemic) Erythromycin (systemic) Clindamycin (topical) Disinfectants Chlorhexidine gluconate (topical) Other Azelaic acid (topical) Contraceptive pill (systemic) |
7 (16) 6 (13) 3 (7) 1 (2) 1 (2) 1 (2) 2 (4) 1 (2) 1 (2) |
| Treatment after diagnosis – topical | |||
| Yes No |
44 (97) 1 (2) |
Antibiotics/combined antibiotics Clindamycin Benzoyl peroxide/clindamycin Clindamycin/tretinoin Disinfectants Chlorhexidine gluconate Other Azelaic acid Resorcinol Triamcinolone acetonide Hydrocortisone |
30 (67) 1 (2) 1 (2) 1 (2) 26 (58) 22 (49) 11(24) 1 (2) |
| Treatment after diagnosis – systemic | |||
| Yes No |
35 (78) 10 (22) |
Antibiotics Tetracycline Combination of rifampicin & clindamycin Doxycycline Amoxicillin/clavulanic acid Roxithromycin Other Metformin Dapsone Adalimumab Acitretin Contraceptive pill |
22 (49) 13 (29) 5 (11) 2 (4) 1 (2) 11 (24) 2 (4) 1 (2) 1 (2) 1 (2) |
| Overall number of shifts in systemic treatment, n (%) | |||
| Median (IQR) Shift No shift Not on systemic treatment Lost to follow-up |
1 (0-1) 18 (40) 7 (16) 11 (24) 9 (20) |
||
| Surgical treatment after diagnosis, n (%) | Surgical procedure | Patients, n (%)* | |
| Yes: 6 (13) No: 39 (87) |
CO2 Deroofing |
4 (9) 2 (4) |
|
| ID/excision | 2 (4) | ||
| IQR: interquartile range; SD: standard deviation; ID: incision and drainage. *Administered to n of patients (%). Some patients had multiple treatments. | |||
Our study has several limitations that need to be considered. First, selection bias might be present in our cohort as only patients referred to a dermatologist by a general practitioner are included in this study. Patients with mild HS might not consult a general practitioner or the consulted practitioner might not refer them to a dermatologist. Second, the medical records were lacking essential data such as BMI and smoking for multiple patients. BMI was not assessed in 32 (71%) of the patients, and data on smoking were lacking in 22 (49%) records. The lack of data prohibited us from correctly characterizing all HS patients. However, a strength of our study is that the results represent all patients in the Faroe Islands seen by a dermatologist and registered under the diagnosis of HS.
Finally, this study is the first prevalence study to be undertaken on the population of the Faroe Islands. The prevalence of HS in the Faroe Islands is an important tool to create awareness of the disease, with the goal of reducing the diagnostic delay and initiate treatment.