Solar keratosis (actinic keratosis): Symptoms, diagnosis and treatment

What is solar keratosis?

Solar (actinic) keratoses are rough areas on the outer skin layer caused by too much exposure to the ultraviolet rays of sunlight. They most often appear after the age of 40, but in some areas where the climate is sunny all year-round these lesions appear in much younger people, even teenagers.

People with fair skin, blonde or red hair, and blue or green eyes are most at risk of developing these rough, scaly "bumps." A history of burning rather than tanning also increases risk. They are usually harmless, but there is a small risk of solar (actinic) keratoses developing into squamous cell carcinoma skin cancer.

To prevent solar (actinic)keratoses, it's important to:

• Avoid exposure to sunlight during peak sunlight hours. (10 a.m. to 4 p.m.)
• Wear clothing that covers arms and legs.
• Wear a wide-brimmed hat (not just a cap) or carry an umbrella during peak sunlight hours.
• Use sunscreen with sun protection factor (SPF) of 15 or higher, applying it at least 15 to 30 minutes before sun exposure, and re-applying regularly whilst outdoors.
• Choose a sunscreen that provides both UVA and UVB protection.
• Remember that it is the light from the sun that can be dangerous (not the heat) so you can be at risk even if the temperature is mild.

What are the symptoms of solar keratosis?

Solar (actinic) keratoses can occur on any area of skin that receives lots of sun exposure -- like the face, ears, the scalp of bald men, and the backs of the hands and arms. The lesion may be skin-coloured, reddish-brown, or yellowish-black. It may look like a raised bump or it may be flat. It may be scaly and dry or not. The skin-coloured lesions may be noticed more by touch because they tend to feel like sandpaper.

It's important to seek medical advice if you notice any new bump or mole, to get it checked out.

What are the treatments for solar (actinic) keratosis?

A number of treatments are available for solar (actinic) keratosis:

They include:

Cryotherapy. Liquid nitrogen ‘freezes’ the surface skin, which causes some skin redness until the area is replaced by new skin.

Surgical removal and biopsy. The lesion may be removed and examined, particularly if there is a possibility it has become cancerous.

Cream or gel. Fluorouracil, salicylic acid, diclofenac or imiquimod may be applied to remove the skin lesion.

Photodynamic therapy. A chemical is applied to the skin, then after several hours it is exposed to a light that activates the chemical to destroy the abnormal skin cells.