Etanercept-induced lichenoid reaction pattern in psoriasis.

We describe a patient with severe psoriasis who was treated with 25 mg subcutaneous etanercept, twice weekly, after several traditional topical and systemic treatments had failed. Our patient initially responded well to etanercept, but after 5 weeks she developed remarkable purple, sharply demarcated, erythematosquamous plaques on the dorsa of both hands, wrists and proximal fingers. Histology showed apoptotic cells and basal vacuolization in addition to a histological picture consistent with moderately active psoriasis. Discontinuation of the drug resulted in a slow regression of the eruption. It is important to realize that a lichenoid reaction pattern may occur during anti-TNFalpha agent treatment.