Psoriasis and psoriatic arthritis induced in a patient treated with infliximab for Crohn's disease.

The induction of psoriasis as a side effect of treatment with TNF-alpha inhibitors is one of a few rare complications of treatment, the pathogenic mechanism of which has not yet been completely clarified. The clinical presentation of these reactions may show the typical characteristics of psoriasis, palmoplantar pustulosis and psoriasiform exanthema; the individual variations of which may combine to give different presentations in individual patients. We present the case of a patient who, after administration of infliximab indicated for Crohn's disease, developed not only skin manifestations but also those of psoriatic arthritis.