Supplementary Material for: A New Perspective on Isotretinoin Treatment of Hidradenitis Suppurativa: A Retrospective Chart Review of Patient Outcomes

Background: Hidradenitis suppurativa (HS) is a disease characterized by the development of painful, deep-seeded nodules and abscesses. Treatment guidelines include a combination of lifestyle, surgical, and medical interventions. Isotretinoin has not been included in the treatment guidelines due to the limited number of studies and conflicting reports of efficacy. Objectives: The purpose of this study is to evaluate the clinical response to isotretinoin in HS patients and to determine whether there is a particular patient population that may benefit more from this treatment. Methods: A retrospective chart review was conducted on all HS patients treated with isotretinoin within the years of 2014-2016. Sex, age, weight, history of acne, Hurley stage, and treatment dose and duration were extracted from patient charts. Results: Of the 25 patients included in the study, 32% (8/25) had no response, 32% (8/26) showed partial response, and 36% (9/25) demonstrated complete response to isotretinoin treatment. Complete response was seen only in Hurley stage I and II patients. Hurley III patients made up 50% of the non-responders. Those with any sort of treatment response were more likely to be female, younger, weigh less, and have a higher prevalence of acne compared to non-responders. Limitations: This is a retrospective chart review with a small sample size of 25 patients. Conclusions: Physicians should consider isotretinoin as a potential treatment for HS, as it may be beneficial in patients with mild and moderate disease and patients who are female, younger, weigh less, and have a personal history of acne.