Treatment of multiple keratoacanthomas with erlotinib.

An 82-year-old male presented with numerous pruritic erythematous nodules over his trunk and extremities. Histopathology was consistent with keratoacanthomas. Given the extent of his disease, medical therapy was recommended. Based on phosphorylated epidermal growth factor receptor expression in lesional keratinocytes, treatment with erlotinib 150 mg daily was initiated, with rapid improvement in the number and appearance of nodules. Immunohistochemistry following treatment revealed a decrease in lesional pEGFR expression, consistent with inhibition of this receptor activation. This is the first report of multiple keratoacanthomas responding to therapy with an EGFR tyrosine kinase inhibitor, and it supports an emerging role for the use of EGFR inhibitors in the management of cutaneous malignancies.