Actinic keratosis is a rough, scaly patch caused by years of ultraviolet damage to the outer skin cells, seen mostly on the face, scalp, ears and hands of fair-skinned older adults. It is a precancerous lesion, and a small share can turn into squamous cell carcinoma.
Key symptoms
- Rough, sandpaper-like spot that is often easier to feel than to see
- Pink, red or skin-colored scaly patches on sun-exposed skin
- Mild itching, burning or tenderness
- Scale that falls off and comes back
What you find on exam
- Small scaly papules or plaques on the face, scalp, ears, forearms and backs of the hands
- Many lesions on a background of sun damage: wrinkles, freckling, spider veins
- Feel for thickness; a firm, tender or growing lesion suggests squamous cell carcinoma
- Check the lips for actinic cheilitis and do a full skin exam
Tests
- Usually a clinical diagnosis
- Dermoscopy helps separate it from other skin lesions
- Shave or punch biopsy if thick, tender, bleeding, ulcerated or not responding to treatment
Treatment basics
- Cryotherapy with liquid nitrogen for a few isolated lesions
- Field treatment for many lesions: topical fluorouracil or imiquimod
- Photodynamic therapy as another field option
- Daily broad-spectrum sunscreen, protective clothing and regular skin checks
Red flags
- Rapid growth, firmness or a thick, hard base
- Bleeding, ulceration or pain
- Many lesions in an immunosuppressed patient, such as after an organ transplant
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.