Condition Basics

What is actinic keratosis?

Actinic keratosis is a skin growth caused by sun damage. It can turn into skin cancer, but this isn't common. Actinic keratoses, also called solar keratoses, are small red, brown, or skin-coloured scaly patches. They are most common on the scalp, face, neck, hands, and forearms.

Your doctor can remove these growths by freezing or scraping them off or by putting medicines on them.

What are the symptoms?

Actinic keratoses are small and noticeable red, brown, or skin-coloured patches that don't go away. They most often occur on the head, neck, or hands but can be found on other areas of the body. Usually more than one is present. They may:

• Have a rough texture.
• Itch, burn, or sting.
• Range in size from 1 mm (about the size of the tip of a pencil) to 2 cm or larger (about the size of a peanut).
• Be numerous, with several patches close together.
• Be surrounded by red, irritated skin.

Actinic keratosis needs to be checked by a doctor, especially if the keratoses become painful, bleed, become open sores, become infected, or increase in size.

How is it diagnosed?

Actinic keratosis is diagnosed through a skin examination. Your doctor may use a bright light or magnifying lens to look for growths, moles, or lesions. The scalp is checked by parting the hair. If there is a chance of cancer, your doctor may take a sample of your skin and test (biopsy) it.

How is actinic keratosis treated?

How is it treated?

Your doctor may recommend one of these treatments:

• Cryotherapy. This involves freezing the skin growth with liquid nitrogen. There is little or no scarring. Cryotherapy can make the treated skin a lighter colour than the nearby skin (hypopigmentation). This colour change may not go away.
• Medicines put on the skin (topical therapy). These include medicines like fluorouracil cream and imiquimod cream.
• Curettage. Treatment involves shaving the growth using a spoon-shaped instrument (curette). After shaving, electrodesiccation may be done to control bleeding and destroy any abnormal cells that remain. Curettage is a quick treatment, but there may be some scarring and changes in the colour (pigment) of your skin.
• Photodynamic therapy (PDT). This uses medicine, such as aminolevulinic acid (ALA), that is put on the skin and then activated with light. The light causes the medicine to destroy the actinic keratosis.
• Chemical peels. Chemicals are applied to destroy the top layer of skin. This is done so new skin can grow and replace damaged skin.
• Laser resurfacing. An intense beam of light from a laser (such as the carbon dioxide laser) is used to destroy the top layer of skin. As the treated area heals, new skin grows to replace the damaged skin.

Will it become cancer?

Actinic keratosis may turn into skin cancer, but this isn't common. There is no way to find out whether actinic keratosis will progress to squamous cell carcinoma or how fast this might occur.

People who have a weak immune system have a higher risk of developing squamous cell carcinoma.

How can you prevent actinic keratosis?

You can help prevent actinic keratosis by staying out of the midday sun and wearing sun-protective clothing. And it helps to use a broad-spectrum sunscreen with a sun protection factor (SPF) of 30 or higher on exposed skin. If you've had these skin growths, you may need to see your doctor for skin checks.