Safety of LEO 43204 for Actinic Keratosis Applied on Face/Chest, Scalp and Trunk/Extremities, Respectively

Inclusion Criteria: Subjects with 5 to 20 clinically typical, visible and, discrete, nonhyperkeratotic and non-hypertrophic AKs within a selected treatment area of sun-damaged skin on either: * The full face * The full balding scalp * A contiguous area of approximately 250 cm2 on trunk or extremities Exclusion Criteria: Location of the treatment area (full face, full balding scalp or chest) within 5 cm of an incompletely healed wound or within 5 cm of a suspected basal cell carcinoma (BCC) or SCC. Previously assigned treatment in this clinical trial or previously participated in a clinical trial in the LEO 43204 programme. Treatment with ingenol mebutate gel in the selected treatment area within the last 12 months Lesions in the treatment area that have: atypical clinical appearance (e.g. cutaneous horns) and/or, recalcitrant disease (e.g., did not respond to cryotherapy on two previous occasions).