Exposome Versus Genome in HS: How Do We Currently Explain Where Disease Arises from?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with marked clinical heterogeneity and a multifactorial pathogenesis. Environmental and lifestyle factors, including obesity, tobacco exposure, microbiome dysbiosis, dietary patterns, and plastic-associated endocrine disruptors, have all been linked to HS risk or disease severity. However, these exposures alone do not fully explain why only some individuals develop HS, why age at onset and severity vary substantially, or why disease occurs in patients without major identifiable environmental burden. In parallel, genetic studies have demonstrated that inherited susceptibility is a central component of HS pathogenesis. Rare loss-of-function variants in γ-secretase complex genes cause a small subset of familial, autosomal dominant HS, while genome-wide association studies have shown that population-level risk implicates pathways involved in epithelial differentiation, follicular biology, immune signaling, and cutaneous inflammation. Recent work further suggests that common and rare genetic risk may converge on shared biological mechanisms, including γ-secretase-related signaling. While nature vs. nurture arguments dichotomize genetic constitution and environmental exposures, current evidence supports a model in which genetic susceptibility interacts with environmental exposures to shape HS risk, clinical expression, and disease progression. In this review, we examine the evidence supporting both exposomic and genomic contributions to HS and argue that the disease is best understood as arising from their intersection rather than from either domain alone.