Actinic keratosis (AK) usually presents as multiple, erythematous or yellow brown, dry, scaly lesions in the sun-exposed areas of the body. It is a lesion of the middle-aged and elderly individuals with a male predominance. It is especially more common in those with fair complexions who burn (rather than tan) upon sun exposure.
The usual sites of involvement are face, trunk, and the dorsal surfaces of the hands and forearms. This image shows AK behind the ear.
The lesions may coexist with lentigo maligna. The surrounding skin shows additional evidence of sun damage, including atrophy, hypo- or hyperpigmentation, and telangiectasia. AK is an indicator of exposure to UV light and predicts the risk of developing squamous cell carcinoma.