Factors associated with therapeutic response to adalimumab in hidradenitis suppurativa: evidence from the Belgian patients of the European Registry for Hidradenitis Suppurativa (ERHS-Be).

Hidradenitis suppurativa is an inflammatory skin disease for which adalimumab is an effective treatment in just over half of cases. Few factors associated with therapeutic response, and therefore potentially predictive of response, are known to date. This real-life study retrospectively explores the existence of such factors in a Belgian cohort of 82 patients, using several response scores: the Hidradenitis Suppurativa Clinical Response (HiSCR), the International Hidradenitis Suppurativa Severity Scoring System-55 (iHS4-55), and the dynamic metascore (a combination of the Hurley score, the 2007 version of the Sartorius score, the iHS4 and the HiSCR). Among the factors associated with a good therapeutic response, we find, for example, the "Frictional furunculoid" and "Conglobata" phenotypes, in contrast to the "Scarring folliculitis" phenotype, which is associated with a poorer response to treatment. Other factors associated with a good response to treatment were observed, such as the patient's description of longer flares, or, among others, the presence of inflammatory bowel disease. Subject to our sample size, the window of opportunity for adalimumab, whereby the treatment would be more effective if administered earlier, was not found in this study.