Actinic keratosis: rough patches from sun damage

What it is

AKs develop in the outer layer of skin after years of sun or tanning-bed exposure. A person may have one visible lesion or a broader “field” of sun-damaged skin containing multiple subtle areas. The number and behavior of individual lesions can change over time.

You cannot reliably distinguish an AK from early squamous cell carcinoma using a photograph. A clinician should examine suspected lesions, particularly when they become thick, tender, rapidly larger or ulcerated.

What it looks and feels like

• A dry, rough, gritty or sandpaper-like patch.
• Pink, red, tan, brown or skin-colored change; color can be subtle on deeper skin tones.
• Scale, crust or a hard horn-like surface.
• Tenderness, burning, itching or sensitivity, though many cause no symptoms.
• Typical sun-exposed locations: bald scalp, face, lip, ears, forearms and backs of hands.

Causes, triggers and risk factors

• Cumulative ultraviolet exposure from sunlight or indoor tanning.
• Outdoor work or hobbies without consistent sun protection.
• Older age, fair skin or tendency to burn—while anyone with substantial UV exposure can be affected.
• Immune suppression, which increases the chance of multiple or aggressive lesions.
• Previous skin cancer or extensive visible sun damage.

Treatment and self-care

A dermatologist may treat a single lesion with cryosurgery or address a wider field using prescription creams, photodynamic therapy or other procedures. Common prescription field treatments include 5-fluorouracil, imiquimod, diclofenac and tirbanibulin; each has different schedules, reactions and contraindications.

Do not borrow another person's prescription or apply wart remover. Protect treated and untreated skin with shade, clothing and broad-spectrum sunscreen. New lesions remain possible because treatment removes visible damage, not the lifetime UV exposure behind it.

Conditions that can look similar

• Squamous cell carcinoma: can be thicker, tender, rapidly growing or ulcerated.
• Seborrheic keratosis: often waxy and “stuck on.”
• Psoriasis or eczema: usually has multiple sites or a recurring inflammatory pattern.
• Superficial basal cell carcinoma: may resemble a persistent pink scaly patch.
• Common wart: rough growth with a different surface pattern.

Can actinic keratosis become cancer?

Most individual AKs do not become invasive cancer, but clinicians cannot predict perfectly which will progress. Having AKs also signals substantial UV damage and a higher overall risk of keratinocyte skin cancers. That is why dermatology organizations recommend assessment and treatment rather than indefinite home observation.

Schedule regular skin checks at the interval your clinician recommends, and perform self-exams between visits. Any lesion that evolves faster than the surrounding sun-damaged spots deserves earlier review.

When to see a healthcare professional

• A rough patch becomes thick, tender, rapidly larger, bleeding or ulcerated.
• A lesion occurs on the lip or you have a weakened immune system.
• You have numerous new rough patches or a history of skin cancer.
• A treated lesion does not resolve or returns.
• You are unsure whether a change is AK or skin cancer.

Sources and further reading

We use established public-health and dermatology references and link them directly so you can verify the guidance and read further.

• Actinic keratosis: diagnosis and treatment — American Academy of Dermatology
• Actinic keratosis overview — National Cancer Institute

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