Successful treatment of keratoacanthoma with intralesional fluorouracil.

Forty-one keratoacanthomas (KA) occurring in thirty patients were treated with weekly intralesional injections of 5-fluorouracil (5-FU). Forty lesions cleared after an average of three injections in an average of 3.4 weeks (range, 2 to 6 weeks). This response suggests that intralesional injections of 5-FU are the treatment of choice for KAs.