Adalimumab-Induced Psoriatic Alopecia/Alopecia Areata-Like Reaction in a Patient with Crohn's Disease

The document discussed a case of a patient with Crohn's disease who developed psoriatic alopecia/alopecia areata-like reaction after treatment with Adalimumab, an anti-TNF-α therapy. The prevalence of psoriasiform eruptions during anti-TNF-α therapy was estimated to be between 1.5 to 5%. The pathophysiology of this paradoxical effect was not fully understood, but two mechanisms were proposed: increased interferon-α production leading to activation of pathogenic T-cells, and induction of a Th17 immune response with down-regulation of Treg cells. The alopecia was characterized by psoriasiform epidermal features and alopecia areata-like dermal changes. The document also mentioned that alopecia is a less well-known side effect of TNF-α inhibitors. After withdrawal of Adalimumab, the patient experienced complete hair regrowth.