Efficacy of topical photodynamic therapy for keratoacanthomas: a case-series of four patients.

Topical photodynamic therapy (PDT) is an excellent treatment option for various non-melanoma skin cancers and precancerous lesions, including actinic keratosis, Bowen's disease, and basal cell carcinoma. The clinical use of PDT includes a broad range of neoplastic, inflammatory, and infectious skin diseases. There is also anecdotal evidence suggesting the efficacy of PDT for the treatment of keratoacanthomas (KA). We report a case-series of four patients with solitary KA confirmed by histology, treated with topical PDT with methylaminolevulinic acid (MAL) cream. After three sessions of PDT, the lesions completely disappeared. There was no evidence of recurrence and excellent cosmetic outcome was achieved after three years of follow-up. Topical photodynamic therapy with MAL can be a therapeutic alternative for KA with good clinical and cosmetic outcomes.