Abstract: Hidradenitis suppurativa (HS) is a chronic, relapsing inflammatory skin disease affecting terminal hair follicles in apocrine-gland-bearing skin. The pathogenesis of HS is still unknown, although increasing evidence suggests that the immune system plays an important role. Herein we describe 3 patients with HS coexisting with autoimmune (Hashimoto's) thyroiditis (AT). To our knowledge, the co-occurrence of these two diseases has not previously been described. The coexistence of HS with autoimmune disorders, such as AT, may support the hypothesis on dysregulation of the immune system's function as implicated in the pathogenesis of HS. Based on our findings, we feel that an assessment of thyroid function and antithyroid antibodies should be performed in patients with HS
