Causes and Risk Factors
Actinic keratoses are the direct result of cumulative UV damage to the outer layer of skin. They are most likely in people with:- Years of sun exposure: Outdoor work, boating, golf, and everyday errands in a sunny climate all contribute; tanning beds add further damage.
- Fair skin that burns easily: Light skin, blond or red hair, and blue or green eyes carry the highest risk.
- Older age: AKs typically appear after 40 and become very common in later decades as damage accumulates.
- A weakened immune system: Transplant medications and some blood disorders let sun-damaged cells grow unchecked, increasing both AKs and skin cancers.
Symptoms
AKs favor the sun-exposed areas: the face, ears, scalp (especially with thinning hair), forearms, and backs of the hands. Typical features include:- A rough, sandpaper-like patch: Often easier to feel than to see, usually less than a quarter-inch across.
- Pink, red, or brown color with dry scale: The scale may flake off and re-form repeatedly in the same spot.
- Itching, burning, or tenderness: Some AKs are irritated by sun, sweat, or shaving.
- A persistent or thickening spot: Unlike patches of dermatitis or facial redness from rosacea, an AK stays fixed in one place and does not clear with moisturizers.
- Lip involvement (actinic cheilitis): Persistent dryness, scaling, and blurring of the lower lip border is a related form of sun damage that deserves evaluation.
Diagnosis
Clinicians usually recognize actinic keratoses by their look and feel during a skin examination. A spot that is unusually thick, tender, growing, or bleeding may be biopsied to make sure it has not already become a squamous cell carcinoma. Because sun damage affects whole regions of skin rather than single spots, the examination usually covers the entire face, scalp, ears, arms, and hands to find additional lesions.Treatment
Treatment removes damaged cells before they can progress. Options depend on how many spots are present:- Cryotherapy: Freezing individual spots with liquid nitrogen is quick and effective; the spot scabs and falls away over a week or two.
- Field treatments: Prescription creams such as 5-fluorouracil or imiquimod treat whole areas of sun damage, clearing visible and invisible AKs together.
- Photodynamic therapy: A light-activated medication destroys precancerous cells across a broad area, useful for the scalp and face.
- Ongoing prevention: Daily sunscreen, hats, and sun-protective clothing prevent new AKs and lower future skin cancer risk.