Impact of interval and combination therapies on the management of actinic keratosis: review and clinical considerations.

Abstract An increasing body of evidence, including epidemiological data, clinical and histopathologic observations, and molecular biological findings, has highlighted the underlying malignant nature of actinic keratosis (AK). Scientific evidence accumulated over the past decade supports the concept that AK should no longer be considered premalignant but instead is now thought to be the earliest stage of a biologic continuum ending in squamous cell carcinoma. This paradigm shift, coupled with a worldwide increase in the incidence of AK, has changed how dermatologists treat AK. These changes include the development of novel topical and procedural therapies; modification of established topical monotherapy regimens to include interval, sequential, short-course, and short-contact therapies; combining various topical therapies; and combining topical and procedural therapies. This review will examine the mechanisms of action and the safety and efficacy data for emerging interval and combination therapies used to treat AK.