Association of hidradenitis suppurativa with autoimmune disease and autoantibodies

OBJECTIVE: There is thought to be an association between hidradenitis suppurativa (HS) and autoimmune diseases. This retrospective longitudinal cohort study looked to identify whether certain autoimmune diseases or autoantibody specificities are more closely associated with HS than others and whether such associations are related to the severity of HS. METHODS: Patients were identified using the SlicerDicer search tool in Epic from 1 January 2010 to 15 August 2020. Search criteria included HS diagnosis by ICD-10 code (L73.2) and at least one visit to the dermatology department. Charts were reviewed to determine HS disease severity, treatment modalities, presence of autoimmune disease and autoantibody positivity. RESULTS: Six hundred and twenty-seven patients were identified. Most patients were female (75.3%) and had obese BMIs (71.1%), but there were no significant demographic differences between HS patients with and without autoimmune diseases. One hundred and one (16.1%) patients in the total cohort had at least one autoimmune disease, most commonly thyroid disease, lupus, psoriasis and IBD. Two hundred and twelve patients were also tested for the presence of autoantibodies. The most common positive autoantibody, found in 54 patients (28.4%), was ANA. Fifty-four patients with more severe HS disease manifestations required biologic medications to treat their HS. Neither HS severity nor biologic treatment was associated with presence of autoimmune disease or positive autoantibodies. CONCLUSION: In a large cohort of patients with HS followed longitudinally, autoimmune disorders (especially lupus, psoriasis and IBD) and presence of autoantibodies were more commonly observed than expected in the normal population.