Psoriasis induced by cetuximab: a paradoxical adverse effect.

Cetuximab, an epidermal growth factor receptor inhibitor, is a chemotherapeutical agent featuring well-known adverse dermatological effects related to tumour-response prognosis. In psoriasis, the epidermal growth factor receptor is overexpressed; hence, the expectation would be that an epidermal growth factor receptor inhibitor could improve psoriatic lesions. We report a case of psoriasis induced by cetuximab, which was a surprising adverse effect.