Multiple modalities exist for the treatment of
keratoacanthoma. Excisional surgery is currently the treatment of choice for the majority of
keratoacanthomas. This can result in functional and cosmetic defects when large or strategically located lesions are treated. An effective nonsurgical treatment would be desirable in such cases. Intralesional
therapy, particularly with
5-fluorouracil, has been shown to be effective in the treatment of
keratoacanthomas. Systemic
methotrexate has been tried, with variable success. We report an open, noncontrolled study of nine consecutive patients with unusually large or strategically located solitary
keratoacanthomas treated successfully with intralesional
methotrexate. All lesions responded promptly, with complete resolution after a mean of 3.0 weeks and a mean of 1.7
injections. No side effects occurred, and
scarring was minimal. We concluded that intralesional
methotrexate is a simple and effective modality for the treatment of select
keratoacanthomas and may offer greater efficacy, a more rapid response, decreased
pain, and lower cost compared with intralesional
5-fluorouracil.