Abstract
Multiple autoimmune syndrome (MAS) is a rare condition, in which at least three well-defined autoimmune diseases co-occur in a single patient. Although the pathogenesis of MAS remains poorly understood, genetic, immunological, hormonal, and environmental factors may all play a role. Although three classic subtypes of MAS are well known, several cases that could not be placed into any of these three categories have recently been reported. To the best of our knowledge, the co-existence of psoriasis, vitiligo, and Crohn's disease has been reported in only one patient, who had a total of five autoimmune diseases (alopecia areata and oral lichen planus in addition to the three conditions mentioned). We herein describe a rare case of MAS presenting with psoriasis, vitiligo, and Crohn's disease, and suggest that tumor necrosis factor-α may be associated with the pathogenesis of all three conditions.