Clinical and demographic features of hidradenitis suppurativa: a multicentre study of 1221 patients with an analysis of risk factors associated with disease severity

Summary Background Hidradenitis suppurativa (HS) is a chronic, relapsing and debilitating inflammatory disease associated with profound morbidity. Aim In this multicentre study, we investigated the demographic and clinical features of HS, and determined risk factors of disease severity. Methods In total, 1221 patients diagnosed with HS from 29 centres were enrolled, and the medical records of each patient were reviewed. Results The mean age of disease onset was 26.2 ± 10.4 years, and almost 70% (n = 849) of patients were current or former smokers. Mean disease duration was 8.9 ± 8.4 years with a delay in diagnosis of 5.8 ± 3.91 years. Just over a fifth (21%; n = 256) of patients had a family history of HS. The axillary, genital and neck regions were more frequently affected in men than in women, and the inframammary region was more frequently affected in women than in men (P