Actinic Keratosis

Actinic keratosis (AK), also known as solar keratosis, is a rough, scaly patch on the skin that develops from years of unprotected exposure to the sun. It is most found on areas frequently exposed to sunlight, such as the face, ears, neck, scalp, hands, and forearms. Actinic keratosis is considered a precancerous condition because it can sometimes develop into squamous cell carcinoma, a type of skin cancer, if left untreated.

Causes: Actinic keratosis is primarily caused by long-term exposure to ultraviolet (UV) rays from the sun or artificial sources like tanning beds. Fair-skinned people, particularly those with lighter hair and eye colors, are at higher risk.

Clinical Features: Actinic keratosis may be solitary but there are often multiple keratoses. The appearance varies.

• Scaly or crusty skin patches: These patches can be red, pink, or brown and may feel dry or rough, like sandpaper.

• Itching or burning: The area may itch, burn, or feel tender.

• Thickening of the skin: The patch may become thicker over time.

Complications: The main concern is that actinic keratoses indicate an increased risk of developing squamous cell carcinoma (SCC). A tender, thickened, ulcerated, or enlarging actinic keratosis is suspicious of evolution to SCC.

Diagnosis: Many providers can diagnose clinically or by dermascopy. Sometimes, a biopsy is necessary, for example, to exclude SCC, or if treatment fails.

Differential Diagnosis: Squamous Cell Carcinoma, Basal Cell Carcinoma, Verruca Vulgaris, Seborrheic Keratosis

Treatment: Options for treating actinic keratosis include:

• Cryotherapy: Freezing the lesion with liquid nitrogen to destroy abnormal cells.

• Topical medications: Creams like 5-fluorouracil, imiquimod, or diclofenac to treat multiple lesions.

• Photodynamic therapy (PDT): A combination of a light-sensitizing agent and a special light to destroy abnormal cells.

• Chemical peels or laser therapy: Sometimes used for extensive areas of AKs.

Prevention: To reduce the risk of developing actinic keratosis:

• Use sunscreen with high SPF daily on exposed skin.

• Wear protective clothing, hats, and sunglasses.

• Avoid tanning beds.

• Stay in the shade when possible, especially during peak sunlight hours.

Regular skin checks with a dermatologist are also important for monitoring and early treatment.

Citation: Coulson, I. (2024, June 1). Actinic Keratosis. DermNet. Retrieved November 10, 2024, from https://dermnetnz.org/topics/actinic-keratosis

Written by Lisa McDaniel, APRN

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