Actinic Keratosis
Also known as: Solar Keratosis, AK
Rough, sandpaper-like patches from years of sun damage. The most common precancer - 5-10% progress to squamous cell carcinoma.
What to look for
Side-by-side comparison
Sun-exposed skin
Smooth texture
Actinic keratosis
Rough, sandpaper-like patch
Actinic keratosis (AK) is the most common precancerous skin lesion, affecting an estimated 58 million Americans. It develops from cumulative ultraviolet radiation damage and represents the earliest stage toward squamous cell carcinoma.
AKs typically appear as rough, dry, scaly patches ranging from 2-6mm. They are often easier to feel than see - running your fingers over sun-exposed skin may reveal a sandpaper-like texture before any visible change. Color varies from skin-toned to pink, red, or brown.
The most common locations are face, ears, bald scalp, neck, backs of hands, and forearms. The critical concern is progression to SCC - while per-lesion risk is 5-10%, patients with multiple AKs face significantly higher cumulative risk. Treatment of all AKs is recommended since predicting which will progress is impossible.
Treatment options include cryotherapy, topical medications (5-fluorouracil, imiquimod), photodynamic therapy, and chemical peels. Having AKs also signals increased risk for all skin cancers including melanoma.
Quick self-check
Does this look like actinic keratosis? Answer 2 questions.
Does the spot feel rough or sandpaper-like?
Is it on a chronically sun-exposed area?
Risk factors
- Cumulative lifetime sun exposure
- Fair skin, light hair, light eyes (Fitzpatrick I-III)
- Age over 40
- High-altitude or equatorial living
- History of sunburns
- Outdoor occupation
- Weakened immune system
- Male sex (2:1 ratio)
When to see a dermatologist
- ⚠Any rough scaly patch on sun-exposed skin persisting more than two weeks
- ⚠A patch that grows, thickens, or develops a raised base
- ⚠A lesion that bleeds or becomes tender
- ⚠Multiple rough spots on sun-exposed areas
- ⚠Any AK not responding to treatment - may indicate SCC progression
Often confused with
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Full ABCDE check →Frequently asked questions
Is actinic keratosis already cancer?
No - AK is precancerous. The malignant cells are confined to the epidermis. If it progresses to invasive SCC (5-10% per lesion), it becomes a true cancer that can spread.
Can AK go away on its own?
Individual AKs may temporarily regress but typically recur. Because you cannot predict which will progress to SCC, dermatologists recommend treating all AKs.
How can I prevent new AKs?
Daily SPF 30+ sunscreen, protective clothing, wide-brimmed hats, and avoiding peak sun hours. Some evidence supports oral nicotinamide (500mg twice daily) reducing new AK development by 11-20%.
Related conditions
Squamous Cell Carcinoma
Second most common skin cancer. More aggressive than BCC - can spread to lymph nodes if not treated early.
Bowen's Disease
Early-stage SCC confined to the top skin layer. A persistent, well-defined red scaly patch - 3-5% progress to invasive cancer.
Solar Lentigo
Flat brown spots from cumulative sun exposure. Completely harmless - but sometimes confused with lentigo maligna (early melanoma).
Seborrheic Keratosis
Waxy, stuck-on growths - the most common benign tumor in adults over 50. Harmless but frequently mistaken for melanoma.