Atypical Dermatitis Herpetiform and Scalp Psoriasis in Ulcerative Colitis Patient Treated With Adalimumab.

Adalimumab is a blocker of tumor necrosis factor (TNF)-alpha with established efficacy in the treatment of ulcerative colitis. However, literature indicated that adalimumab can, occasionally, induce paradoxical psoriasis reactions and, very rarely, dermatitis herpetiformis. We present a unique case of a 26-year-old female patient who developed a combination of dermatitis herpetiformis and scalp psoriasis paradoxically as a result of adalimumab treatment for ulcerative colitis. To the best of our knowledge, this is the first case of such a combination within the context of adalimumab therapy. The etiopathological underpinning of such a reaction remains elusive but is speculated to be complex and involves the interaction of several immunological and dermatological mechanisms. Adalimumab therapy is associated with a genuine risk for the development of paradoxical psoriasis and dermatitis herpetiformis. We, through this case report, added to the evidence confirming such an association. Clinicians should follow these potential adverse effects and make every effort to warn patients of their likelihood.