Phenotypic heterogeneity in hidradenitis suppurativa (acne inversa): classification is an essential step toward personalized therapy.

Awareness is increasing that there is phenotypic heterogeneity within the hidradenitis suppurativa (HS) disease spectrum. However, the few randomized HS trials that are available have not distinguished between the subtypes of the disease. In this issue, Canoui-Poitrine et al. used latent class (LC) analysis of the largest HS cohort described to date to generate three phenotypic subtypes. LC 1 correlates with "typical" European HS, mainly involving the axilla, groin, and, in women, the inframammary region. "Atypical" HS, which may be linked to γ-secretase gene mutations, was subdivided further into LC2 and LC3 subtypes.