Incidence of Deep Vein Thrombosis and Pulmonary Embolism in Patients with Hidradenitis Suppurativa.

INTRODUCTION: The risk of thromboembolism in patients with hidradenitis suppurativa (HS) has not been established. This study aimed to estimate the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) among adults with HS and demographic subgroups. METHODS: This retrospective cohort study was conducted between January 1, 2017, and December 31, 2024, using a health insurance claims database (Optum Clinformatics DataMart) in the US. Adults aged ≥ 18 years with an outpatient visit linked to a diagnosis of HS or any other diagnosis (controls) were eligible. Patients with prior diagnosis of either outcome or associated conditions were excluded. The primary outcomes evaluated were new-onset DVT and PE. RESULTS: Mean (SD) age was 43 (16) years for eligible patients with HS (n = 44,520) and 54 (19) years for control patients (n = 3,792,627). Incidence of DVT was 3.0 (95% CI 2.5-3.4) and 3.5 (95% CI 3.4-3.5) per 1000 person-years (PY) in patients with HS and controls, respectively. Incidence of PE was 2.4 (95% CI 2.0-2.8) and 2.2 (95% CI 2.2-2.3) per 1000 PY in patients with HS and controls, respectively. In demographics-adjusted analyses, standardized incidence ratios for DVT and PE were 1.42 (95% CI 1.23-1.65) and 1.78 (95% CI 1.50-2.10), respectively. Comorbidity-adjusted hazard ratios for DVT and PE were 1.12 (95% CI 0.97-1.31) and 1.35 (95% CI 1.14-1.60), respectively. Incidence of DVT was higher in patients with HS by a factor of 1.5-2.9 for age subgroups between 45 and 74 years, with absolute incidence rates ranging from 3.5 to 8.8 per 1000 PY. Incidence of PE was higher in patients with HS by a factor of 1.5-3.2 across age subgroups between 45 and 74 years, with absolute incidence rates ranging from 3.0 to 5.4 per 1000 PY. CONCLUSION: Patients with HS have a significantly higher incidence of both DVT and PE relative to demographically similar patients without HS. This information may support counseling on risk mitigation strategies and safety monitoring during treatment and may provide context for observed (versus expected) thrombotic events in clinical trials for HS.