Actinic keratosis

Actinic keratoses are precancerous skin lesions that can appear after the age of 40 years and have a scaly appearance, caused by frequent or intense exposure to ultraviolet (UV) rays from the sun or from artificial sources, such as tanning beds.

• Prolonged exposure to UV rays (both recreational and occupational).
• Having a history of intense sun exposure or sunburn increases the risk.
• Having a pale skin phototype and a tendency to freckle or burn with sun exposure increases the risk.
• The prevalence of actinic keratosis is higher in men than in women.
• People with compromised immune systems, such as those who have received organ transplants, are more susceptible.
• The presence of other pathologies such as diabetes, rheumatoid arthritis and psoriasis may influence the development of actinic keratosis.

Actinic keratosis is most common in regions of skin chronically exposed to the sun. Lesions appear as thin or raised papules with a reddish-brown or yellowish-black color or appear as plaques with an appearance of dry adherent scales. The lesions may be asymptomatic or cause itching, burning or tenderness. Occasionally they may bleed or crust over.

Actinic keratosis may progress to squamous cell carcinoma in approximately 10% of cases, so these patients should be followed regularly.

Sun protection helps prevent actinic keratosis. The following measures are recommended to protect the skin from the sun:

• Use broad-spectrum sunscreen with a sun protection factor (SPF) of at least 30 and apply it before sun exposure and regularly, every two hours or so, while you are exposed. Use sunscreen also on cloudy days.
• Wear protective clothing and a wide-brimmed hat that provides greater protection than hats and visors.
• Reduce the amount of sun exposure time and avoid exposure between 10:00 am and 2:00 pm.
• Avoid sunbeds and other sources of artificial UV light.
• Inform your doctor if you notice new growths or changes in existing moles, freckles, bumps and birthmarks.