This report of the baseline characteristics from UNITE, a non-interventional long-term hidradenitis suppurativa (HS) registry, provides the first geographically diverse, detailed clinical description of HS in an observed population across North America, Europe, and Australia.

Clinical aspects of the disease appeared similar between adults and adolescents, although adolescents were more likely to have been diagnosed earlier in the disease course.

Lesion count and scarring affected the groin/pelvic/pubic area most commonly and severely compared with the inframammary area, in contrast to previous reports.