Actinic Keratoses
Actinic keratoses are precancerous, sun-damage-related skin lesions, managed per the AAD 2021 Guidelines of Care and the NCCN squamous cell skin cancer guideline.
Symptoms
Rough, dry, scaly patches, often easier to feel than see, most common on chronically sun-exposed skin -- the face, ears, scalp, and forearms.
Causes and risk
Cumulative UV exposure causes DNA damage (including to the p53 tumor-suppressor gene) in skin cells; fair skin, older age, and a history of significant sun exposure or tanning bed use all raise risk.
How it is evaluated
Diagnosis is usually clinical; atypical, thickened, tender, or treatment-resistant lesions should be biopsied to rule out progression to squamous cell carcinoma.
Treatment
Cryotherapy, topical 5-fluorouracil, and topical imiquimod all carry strong recommendations in the AAD guideline; photodynamic therapy is conditionally recommended for widespread field damage.
When to seek care
A lesion that becomes rapidly growing, thickened, tender, bleeding, or ulcerated should be evaluated promptly -- these are the features that can signal progression to squamous cell carcinoma. A single AK carries roughly a 0.5-1% per-year risk of becoming SCC, but a diagnosis of AK marks a substantially higher long-term skin-cancer risk overall, per cohort data.