This is a prospective, non-interventional study of adult patients prescribed topical treatment with ingenol mebutate gel (Picato®) as part of provision of care for the treatment of Non-hyperkeratotic, non-hypertrophic Actinic Keratosis (AK). Patients with complete clearance at 8 weeks will be followed for one year or until retreatment of AK in the area initially treated, whatever comes first. For patients with incomplete clearance in the treated area at 8 weeks the treatment strategy for this area will be recorded but no further follow-up will take place. The effectiveness, tolerability, adherence, patient satisfaction and health-related quality of life (HRQoL) associated with Picato® treatment will be evaluated.