Assessment tools and phenotype classification for hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a heterogeneous chronic relapsing skin disease. Several assessment tools are used to assess disease severity and to classify disease phenotype; however, no consensus exists. This review evaluates the various assessment tools and phenotypes, assessing their validity and reliability. Numerous assessment tools and phenotype classifications have been proposed for identifying various subtypes within the hidradenitis suppurativa disease spectrum. Each has a different purpose, such as use in daily practice or in clinical trial settings. Several assessment tools and phenotype classifications have been validated but not always with satisfactory results and often with studies showing divergent intra-rater reliability results. A consensus is needed for a validated, easy-to-use, and timesaving assessment tool for routine daily practice. For clinical trials, a validated and extensive assessment tool that also measures response to treatment is also needed.