Hidradenitis Suppurativa and Thyroid Disease: Systematic Review and Meta-Analysis.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by painful nodules, sinus tracts, and significant scarring. Although the pathogenesis of this disease is not well established, there is increasing evidence to suggest that it is an immune-mediated disorder. Previous studies have suggested a relationship between HS and thyroid disease, which is also driven by an autoimmune process. We sought to assess whether an association exists between HS and thyroid disease. OBJECTIVES: To determine whether HS is associated with thyroid disease via meta-analysis of case-control studies. METHODS: A systematic review and meta-analysis was performed according to recommended PRISMA guidelines. Electronic searches were performed using 6 electronic databases from their inception until August 2018. Data were extracted and analyzed according to predefined clinical endpoints. Odds ratio (OR) was used as the summary effect size. RESULTS: We identified 5 case-controls studies included for meta-analysis. There were a total of 36 103 HS cases compared with 170 517 control cases. We found a significant association between HS and thyroid disease (OR 1.36, 95% CI 1.13-1.64, I 2 = 78%, P = .001). CONCLUSIONS: This pooled analysis of existing case-control studies to date supports an association between HS and any thyroid disease. Clinicians treating patients with HS should be aware of this potential association with thyroid disease.