Actinic keratoses (solar keratoses) are precancerous growths caused by long-term sun exposure.
Many years of sun exposure can cause actinic keratoses to develop on the skin.
Actinic keratoses are rough and scaly and appear in various colors.
The diagnosis is usually based on a doctor's evaluation.
Growths can be removed by physical means or by various treatments applied to the skin.
(See also Overview of Sunlight and Skin Damage.)
Actinic keratoses are very common. As people age, they are likely to develop them. Actinic keratoses can progress to squamous cell carcinoma, a type of skin cancer. Growths that do not progress to squamous cell carcinoma may go away or stay actinic keratoses. Growths that go away may return.
In addition to many years of sun exposure, other risk factors for actinic keratoses include older age, an impaired immune system, blond or red hair, blue eyes, and skin type I or II (see table Fitzpatrick Skin Type Classification).
Fitzpatrick Skin Type Classification
Skin Type | Typical Features | Tanning Ability |
|---|---|---|
I | Pale white skin; red or blond hair; blue/green eyes; freckles | Always burns, never tans |
II | Fair skin; red or blond hair; blue, hazel, or green eyes | Burns easily, tans with difficulty |
III | Darker white; any eye or hair color | Sometimes mild burn, gradually tans |
IV | Light brown skin | Burns only slightly, tans easily |
V | Brown skin | Rarely burns, easily tans darkly |
VI | Dark brown or black skin | Never burns, always tans darkly very easily |
Symptoms of Actinic Keratoses
Actinic keratoses are usually pink, red, or, less commonly, gray or brown. They feel rough and scaly.
The growths frequently develop in sun-exposed areas (for example, lips, bald scalp, face, neck, or the backs of hands and forearms).
Diagnosis of Actinic Keratoses
A doctor's examination
Doctors diagnose actinic keratoses by looking at and touching them. Because of their rough texture, actinic keratoses are often easier to feel than see. Doctors also differentiate them from seborrheic keratoses, which can look similar to actinic keratoses.
Treatment of Actinic Keratoses
Physical removal or products applied to the skin
People should take precautions to minimize the damaging effects of the sun (see sunburn prevention). Damage that is already done is difficult to reverse.
Actinic keratoses are treated depending on the number of growths, where the growths are located, and what therapy people can tolerate.
If a person has only a few growths or is unable to tolerate other treatments methods, doctors usually remove them by freezing them with liquid nitrogen (cryotherapy) or scraping (curetting) them off. These treatment options are the quickest but have a higher risk of leaving a scar compared to other treatment options.
Another treatment is photodynamic therapy, in which a chemical preparation is applied to the skin and then artificial light is applied to the growths. This therapy causes a sunburn-like appearance. The main advantage of photodynamic therapy is that it typically entails fewer days overall of skin redness, scaling, and irritation. People may need more than one treatment session.
If a person is not helped by any of these treatments, doctors may do a biopsy to rule out squamous cell carcinoma.
