An actinic keratosis is the most common precancerous lesion of the skin. Actinic keratoses are caused from sun exposure. Early on in development, they may appear intermittently on sun-exposed skin. Actinic keratoses are rough to touch and may be easier to feel than see. They are usually red in color and either scaly or crusted.
Left untreated, actinic keratoses may transition to squamous cell carcinoma. Numerous treatment options are available. Frequently, treatment with liquid nitrogen (freezing) is performed in the office as treatment.