Actinic (Solar) Keratoses

ActinicActinic Keratoses are rough or warty areas of skin found mainly on sun-exposed parts of the body, particularly the backs of the hands and forearms, the face and ears, the lower legs in women and the scalp in balding men.   Usually they are harmless but there is a small risk of some actinic keratoses developing into a form of skin cancer called squamous cell carcinoma.   If an actinic keratosis starts to grow into a lump, becomes itchy or tender or bleeds, medical advice should be sought as these changes could indicate the development of a skin cancer.

What causes actinic keratoses?

They are caused by sun exposure over many years (from sunbathing or just being outdoors) and so are more common in older people. People with fair skin and blue/green eyes who burn easily in the sun are most at risk.

What do actinic keratoses look like?

Actinic keratoses vary in their appearance.   They can even differ from one another within the same person.   At first they can be hard to see, and are more easily felt – being rough, dry or scaly. They may grow up to a centimetre or two in size.   Some are skin coloured, others are pink, red or brown.   They can become raised, hard and warty.   They may be solitary or multiple.

How are actinic keratoses diagnosed?

They are diagnosed from their appearance by a GP or dermatologist, but in cases of doubt, for example if an early skin cancer is suspected, a sample (or the whole lesion) may be removed under a local anaesthetic for laboratory examination under the microscope.

Is there a cure for actinic keratoses?

Yes – but others may develop in the future from the surrounding sun-damaged skin.

How can actinic keratoses be treated?

Sometimes small actinic keratoses may disappear spontaneously. It is still important to protect the skin from the sun (for example, by wearing a hat, long sleeves and a high factor sunblock), as this can help to reduce the frequency of appearance of further actinic keratoses.

It is advisable to treat more persistent, extensive and larger actinic keratoses as there is a small risk of some of them transforming into a skin cancer.

Treatments used for actinic keratoses:

  • Freezing with liquid nitrogen (cryotherapy). This is an excellent, effective treatment for small superficial actinic keratoses.
  • Surgical Removal. This requires local anaesthetic (injection), after which the actinic keratosis can be scraped off with a sharp spoon-like instrument (a curette), or it can be cut out and the wound closed with stitches. Surgical removal leaves a scar but provides a specimen that can be analysed in the laboratory to confirm the diagnosis of an actinic keratosis and exclude a skin cancer.
  • Creams. Various creams containing a drug called 5-fluorouracil (efudix), imiquimod (aldara), retinoids or diclofenac can be useful treatments for actinic keratoses, especially if there are a lot of them.   These preparations work by selectively destroying the abnormal cells in skin that has been damaged by the sun.   They do not affect normal skin, however, they often cause a lot of redness and inflammation of the treated areas.   Treatment may be for up to 3 months depending on the type of cream used and the extent of the actinic keratoses.