Psoriasis induced by anti–tumor necrosis factor therapy: A paradoxical adverse reaction

Abstract

Administration of anti–tumor necrosis factor (anti‐TNF) agents is beneficial in a variety of chronic inflammatory conditions, including psoriasis. We describe 5 patients in whom psoriasiform skin lesions developed 6–9 months after the initiation of anti‐TNF therapy for longstanding, seropositive rheumatoid arthritis (etanercept or adalimumab), typical ankylosing spondylitis (infliximab), and Adamantiades‐Behçet's disease (infliximab). In all 5 patients, the underlying disease had responded well to anti‐TNF therapy. Four patients developed a striking pustular eruption on the palms and/or soles accompanied by plaque‐type psoriasis at other skin sites, while 1 patient developed thick erythematous scaly plaques localized to the scalp. In 3 patients there was nail involvement with onycholysis, yellow discoloration, and subungual keratosis. Histologic findings from skin biopsies were consistent with psoriasis. None of these patients had a personal or family history of psoriasis. In all patients, skin lesions subsided either with topical treatment alone, or after discontinuation of the responsible anti‐TNF agent. The interpretation of this paradoxical side effect of anti‐TNF therapy remains unclear but may relate to altered immunity induced by the inhibition of TNF activity in predisposed individuals.