Topical 5-aminolaevulinic acid photodynamic therapy for extensive scalp actinic keratoses.

Scalp actinic keratoses (AKs) are common, particularly in elderly bald males. Cryotherapy and 5-fluorouracil are effective for localized AKs but are limited in extensive disease. Topical 5-aminolaevulinic acid photodynamic therapy (5-ALA PDT) is an alternative. We treated four patients with extensive scalp AKs with low light dose, low dose-rate topical 5-ALA PDT using a broad-spectrum visible light source. Three patients cleared and one showed significant improvement. Remission lasted 6 months.