Supplementary Material for: Proposed Definitions of Typical Lesions in Hidradenitis Suppurativa

Background: Although not rare, hidradenitis suppurativa (HS) is often under-recognized by physicians. The diagnosis of HS is clinical via the recognition of lesions typical of the disease, but universally accepted definitions of these latter are currently lacking, which means that certain severity scores employed for HS classification/management are used differently by different physicians. Our aim was to develop a set of descriptive definitions and associated images of HS lesions, in order to enable doctors to better recognize and evaluate the disease. Methods: MEDLINE-available literature and dermatological textbooks on HS morphology were retrieved (January 1996 to February 2016). A preliminary set of definitions of HS typical lesions was created, including 10 terms. Each term was associated with a pathophysiological classification and an image. This preliminary set was shown during the 5th Conference of the European HS Foundation (EHSF). The physicians attending the event were invited to vote on each term and make comments via a voting sheet. Results: A total of 81 physicians answered the questionnaire. Their agreement/disagreement rates and comments were used to obtain a revised set of definitions and images. Pathophysiological classifications were dropped. Conclusion: A user-friendly set of definitions/images of HS typical lesions was proposed and will need to be validated by further studies. This set could ultimately serve as a tool to better recognize, score, and assess treatment efficacy.