Risk of fracture in patients with hidradenitis suppurativa: A multi-center retrospective cohort study

The association between chronic inflammatory dermatoses and impaired skeletal health is an area of growing interest. While recent research suggests that patients with hidradenitis suppurativa (HS) have underlying structural bone deficits, large-scale data remain limited on whether this translates into an increased risk of tangible clinical outcomes, particularly incident fractures at the population level. This study therefore aimed to quantify the independent risk of new-onset fractures in patients with HS. In this multi-center retrospective cohort study using de-identified data from the U.S. TriNetX network (2005–2018), patients with HS were compared to non-HS controls after 1:1 propensity score matching to balance a wide range of demographic and clinical confounders. Individuals with a prior history of fracture, osteoporosis, or malignancy were excluded. The primary outcome was any new incident fracture over a maximum follow-up of 15 years. The final analysis included 51,773 matched pairs. Patients with HS demonstrated a significantly increased risk of overall fracture compared to controls (HR: 1.25, 95% CI: 1.19–1.31). Site-specific analyses revealed an elevated risk for vertebral (HR: 1.66, 95% CI: 1.38-2.00), proximal humeral (HR: 1.52, 95% CI: 1.19–1.93), and lower limb fractures (HR: 1.33, 95% CI: 1.19–1.48), whereas no significant association was found for hip or wrist fractures. The association remained robust across numerous sensitivity analyses and was consistent when stratified by age and sex. Notably, the fracture risk in HS was significantly higher than in active comparator cohorts with psoriasis (HR: 1.24, 95% CI: 1.17–1.31) and alopecia areata (HR: 1.12, 95% CI: 1.02–1.23). In conclusion, this large-scale study provides compelling evidence that HS is an independent risk factor for incident fractures. These findings highlight the need for bone health surveillance in the multidisciplinary management of HS. Future research should utilize prospective study designs to confirm such associations and investigate the possible biological mechanisms underlying these associations.