Actinic keratoses are common skin lesions associated with solar ultraviolet radiation exposure. Some actinic keratoses may develop into skin cancers.~Imiquimod 3.75% cream is an approved treatment for actinic keratoses that utilizes a regimen of application to the entire face or balding scalp of up to 2 packets of cream daily for two 2-week cycles, separated by a 2-week no treatment interval.~Photodynamic therapy with aminolevulinic acid (ALA) 20% topical solution is also an approved treatment for actinic keratoses. ALA is applied to actinic keratoses, and after an incubation period, is excited with light. Although approved as a lesion-directed treatment for actinic keratoses, treatment of a field (e.g. face) with photodynamic therapy is commonly performed.~Treatment with photodynamic therapy followed by imiquimod 5% cream has been reported in patients with actinic keratoses, basal cell carcinoma and Bowen's disease, and treatment with imiquimod 5% cream followed by photodynamic therapy in patients with vulvar intraepithelial neoplasia. There are, however, no prior studies on the safety and/or efficacy of using topical imiquimod 3.75% in conjunction with photodynamic therapy in the treatment of actinic keratoses.~This study will use an open-label parallel cohort design in which all patients will received treatment with imiquimod 3.75% cream, and subsequently will be randomized to either photodynamic therapy or observation.
The purpose of this study is to explore the effect of treating actinic keratoses of the face with imiquimod 3.75% cream followed by photodynamic therapy in comparison to treatment with imiquimod alone