Association between Hidradenitis Suppurativa and Inflammatory Arthritis: A Systematic Review and Meta-Analysis

BACKGROUND: Several studies report a high prevalence of inflammatory arthritis among hidradenitis suppurativa (HS) patients. OBJECTIVES: To study the association between HS and inflammatory arthritis. METHODS: The systematic review and meta-analysis were performed according to the PRISMA guidelines to identify the association between HS and inflammatory arthritis, spondyloarthritis, ankylosing spondylitis (AS), and rheumatoid arthritis (RA). RESULTS: Seven studies were entered in the analysis, with 200,361 HS patients and 385,599 controls. Pooled analysis illustrated a significantly increased risk of inflammatory arthritis in HS patients compared to controls (odds ratio OR 3.44; 95% confidence interval CI 1.92-6.17). There was also a statistically significant association between HS and spondyloarthritis (OR 2.10; 95% CI 1.40-3.15), and between HS and AS (OR 1.89; 95% CI 1.14-3.12). Moreover, pooled analysis showed a statistically significant association between HS and RA (OR 1.96; 95% CI 1.28-2.98). CONCLUSIONS: Our findings show that HS patients have a 3-fold increased risk of developing inflammatory arthritis. HS patients are specifically at a higher risk for spondyloarthritis, its subtype AS, and RA.