Cutaneous adverse reaction to infliximab: report of psoriasis developing in 3 patients.

Infliximab is a chimeric immunoglobulin G1kappa monoclonal antibody against tumor necrosis factor alpha (TNF-alpha), a proinflammatory cytokine that participates in both normal immune function and the pathogenesis of many autoimmune disorders. Treatment with infliximab reduces the biologic activities of TNF-alpha and thus is indicated in the treatment of rheumatoid arthritis, Crohn disease, ankylosing spondylitis, psoriatic arthritis, plaque psoriasis, and ulcerative colitis. To our knowledge, there have been 13 case reports of new-onset psoriasis, psoriasiform dermatitis, and palmoplantar pustular psoriasis that developed during treatment with infliximab. We report 3 additional cases of biopsy-proven new-onset psoriasis that developed while the patients underwent treatment with infliximab for inflammatory bowel disease. Although the mechanism for the development of psoriasis in these patients is unclear, several possible explanations are proposed. With increasing use of infliximab and other TNF-alpha inhibitors in clinical practice, more cases of similar reactions to these drugs probably will be reported and are necessary to determine the importance of this eruption.