Actinic keratoses

Published by Bupa's Health Information Team, November 2010.

This factsheet is for people who have actinic keratoses, or who would like more information about them.

Actinic keratoses, or solar keratoses, are skin lesions that appear with age and are in part caused by long-term sun exposure. Patches of rough, scaly skin often develop on the backs of the hands, forearms and face. If left untreated, actinic keratoses can progress to skin cancer, but this is very rare.

About actinic keratoses

Actinic keratoses are common skin lesions that develop as a result of ageing and long-term exposure to the sun. In the UK, about one in four people aged 60 and over have actinic keratoses.

The rough, scaly patches of skin that develop (actinic keratoses) are usually harmless. They develop when your skin can’t repair the damage that has been caused by long-term sun exposure. It’s possible that some of the cells can become increasingly abnormal and develop into a type of skin cancer called squamous cell carcinoma (SCC), but this is very rare. If your actinic keratoses become very itchy or form a nodule with crusting on your skin, you must see your GP as this can be an early sign of skin cancer.

Symptoms of actinic keratoses

At first you may notice small, rough spots on areas of your skin that are frequently exposed to sunlight – such as the skin on your face, ears, forearms and hands. They can, however, develop anywhere on your body that is repeatedly exposed to the sun. The spots can feel similar to rubbing sandpaper and can be itchy. They may also come and go.

Most actinic keratoses are about 0.5 to 1cm wide. Over time, the spots may get bigger (up to about 2cm) and usually become red and scaly. However, their appearance can differ hugely. For example, they may be skin-coloured, pink or brown. Also, they can become raised, hardened and wart-like and may even develop a small horn-like growth. Equally, they can remain soft or flat. The skin surrounding the actinic keratoses often looks sun-damaged, for example blotchy, freckled and wrinkled.

If you have any of these symptoms, see your GP.

Complications of actinic keratoses

Most actinic keratoses are usually harmless and will not turn into SCC. Treatment can be effective if the cancerous changes in your skin are diagnosed early. See our Skin cancer factsheet for more information.

See your GP straight away if your actinic keratoses start to grow into a lump, become itchy, tender or bleed.

Causes of actinic keratoses

Actinic keratoses are caused by ageing of the skin and repeated exposure to ultraviolet (UV) radiation from the sun. The more time you have spent in the sun throughout your life, the more likely you are to develop the condition. This is the reason that people living in sunny countries such as Australia have a higher risk of developing actinic keratoses.

You may also be more at risk of developing actinic keratoses if you:

• are fair-skinned, with blue eyes and blonde or red hair
  
• tend to burn rather than tan
  
• use sunbeds
  
• have a weakened immune system – for example if you have HIV/AIDS, or take medicines that suppress your immune system
  
• have certain genetic conditions, such as xeroderma pigmentosum (where sun exposure causes increased sensitivity to the sun) or albinism (where you have no pigment in your skin, hair and eyes)

Diagnosis of actinic keratoses

Your GP will ask about your symptoms and examine your skin. The appearance and distribution of the actinic keratoses on your body are usually enough to confirm a diagnosis.

If the actinic keratoses become very itchy, grow or bleed, you may be referred to a dermatologist (a doctor who specialises in identifying and treating skin conditions). He or she may take a sample of your skin (known as a biopsy) under a local anaesthetic, to check for skin cancer. This will be sent to a laboratory for testing.

Treatment of actinic keratoses

Depending on the severity of your condition; your GP will be able to advise you about which treatment is most suitable. Sometimes, actinic keratoses can disappear on their own. If you have been diagnosed with actinic keratoses, you should always take extra care in the sun (see Prevention).

Topical medicines

Your GP may prescribe one of the following topical medicines to treat actinic keratoses. A topical treatment is a medicine you apply directly to your skin.

• Diclofenac gel. This can be effective in clearing mild actinic keratoses. You apply a thin layer of the gel twice a day for up for three months.
  
• Fluorouracil cream. This can be used for most types of actinic keratoses (mild to severe). You apply a thin layer of the cream to the affected area, usually once a day, for about four weeks. Don’t apply this cream if you are pregnant or breastfeeding as it can cause harm to your baby.
  
• Imiquimod cream. You rub the cream directly onto the affected area. The treatment is usually repeated five times a week for four weeks. If the actinic keratoses haven’t improved after treatment, you may need a further four week course.

These treatments can cause side effects such as itching, redness and rashes, but usually go away soon after you stop applying them. Always ask your GP for advice and read the patient information leaflet that comes with your medicine.

Cryotherapy

This involves freezing the actinic keratoses off with liquid nitrogen. Cryotherapy is less likely to leave a scar than surgery, but can sometimes leave a pale mark. It's usually done when there are only a few small actinic keratoses on your skin as it can be quite painful.

Photodynamic therapy

This involves scraping off the crusted surface of the actinic keratoses and applying a special cream, which contains a chemical that is only absorbed by sun-damaged cells. A special light is then shone on the area to activate the chemical and destroy the sun-damaged cells. If necessary, the treatment can be repeated.

Surgery

If you have thickened and horn-like actinic keratoses, your GP or dermatologist may decide to surgically remove them. This is done under a local anaesthetic. The actinic keratoses can be scraped off with an instrument called a curette or may be cut out if your doctor suspects that a skin cancer may have developed. All these procedures will leave a scar. Samples can be taken from the actinic keratoses to send to a laboratory for testing. This can confirm your diagnosis and determine whether there are any signs of skin cancer.

Prevention of actinic keratoses

Developing actinic keratoses is a sign that your skin is ageing and has been damaged by the sun over a lifetime. You can reduce your risk of developing actinic keratoses or, if you already have it, prevent your condition from becoming any worse, by doing the following.

• Stay out of the sun when the sun is at its strongest – this is between 11am and 3pm in the UK in summer. Times can vary in different countries.
  
• Use at least factor 30 sunscreen when in the sun. Make sure that it protects you from UVA and UVB radiation. UVA protection may be shown with a star rating between zero and five, with five stars being the highest level of protection. Re-apply it every two hours.
  
• Wear a broad brimmed hat and long sleeves to protect the most sun-exposed areas of your skin.
  
• Use sun glasses that have UV protection.
  
• Never use a sunbed.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.