Actinic keratoses are rough, superficial lesions usually found on the sun exposed areas of the body, particularly the face and upper extremities in people with fair complexions. These lesions are considered precursors of squamous cell carcinoma. They can occur as solitary lesions or can be found in considerable numbers, and they are the direct result of excessive sun exposure in the patients’ early childhood and young adult life. Once they start to appear, there is a propensity for them to increase in number even if sun exposure is significantly curtailed. The rough spots can often be felt better than seen. Actinic keratoses are a sign of excessive sun exposure and are considered a marker for developing skin cancer.
A cutaneous horn is a hard, horny projection on the skin. A nodule frequently develops under the horn, pain or tenderness can occur. These lesions become squamous cell carcinoma in situ (limited to the epidermis). With more time, invasive squamous carcinoma develops.
Many treatment options are available to address these lesions. Liquid nitrogen is commonly used to treat individual lesions, while numerous lesions may be treated with field effect therapy, such as blue light or topical creams.