What are the aims of this leaflet?

This leaflet has been written to help you understand more about actinic keratosis. It tells you what they are, what causes them, what can be done about them, and where you can find out more about them. Another name for ‘actinic keratosis’ is ‘solar keratosis’, but for convenience we shall use only the term ‘actinic keratosis’ in this leaflet.

What are actinic keratosis?

Actinic keratosis are areas of sun-damaged skin found predominantly on sun-exposed parts of the body, particularly the backs of the hands and forearms, the face and ears, the scalp in balding men and the lower legs in women. They may also occur on the lips. The terms actinic and solar are from Greek and Latin, respectively, for ‘sunlight-induced’, and the term keratosis refers to thickened skin. They are usually harmless but there is a very small risk of some actinic keratosis progressing to a form of skin cancer called squamous cell carcinoma (see Patient Information Leaflet on Squamous Cell Carcinoma). Actinic keratosis are not contagious.

What causes actinic keratosis?

They are caused by excessive sun exposure over many years (from sunbathing, sunbed use, and outdoor work or recreational activities) and are therefore more common in older people. Fair-skinned, blue-eyed, red- or blonde-haired individuals, who burn easily in the sun but tan poorly, are at particular risk.

Are actinic keratosis hereditary?

No, but some of the factors that increase the risk of getting actinic keratosis such as a tendency to burn rather than tan, and freckling, do run in families.

What are the symptoms of actinic keratosis?

They often cause little trouble. Many affected individuals are not aware of them at all. The affected skin feels rough and dry. However, if an actinic keratosis starts to grow into a lump, becomes itchy, tender or starts to bleed, medical advice should be sought as these changes could indicate the development of skin cancer (a squamous cell carcinoma).

What do actinic keratosis look like?

Actinic keratosis can be variable in appearance, even differing from one another within a single individual. At first they can be hard to see, and are more easily felt, being rough, like sandpaper. They may grow to a centimetre or two in diameter. Some are skin coloured, others are pink, red or brown. They can become raised, hard and warty, and may even develop a small horny outgrowth. The surrounding skin often looks sun-damaged – blotchy, freckled and wrinkled.

How are actinic keratosis diagnosed?

Usually the appearance of an actinic keratosis is sufficient to enable the diagnosis to be made, but in cases of doubt, for example if an early skin cancer is suspected, a sample (biopsy) or the whole affected area may be removed surgically under local anaesthetic for microscopic examination in the laboratory.

Can actinic keratosis be cured?

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

How can actinic keratosis be treated?

It is advisable to protect the skin from further sun damage (for example, by wearing a hat, long sleeves and a sunscreen with a high sun protection factor). (See Leaflet on Sunscreens)

Occasionally, small actinic keratosis may go away spontaneously, but generally they are treated as there is a small risk that some might transform into a skin cancer.

Treatments used for actinic keratosis include the following:

·    Freezing with liquid nitrogen (Cryotherapy). This is an effective treatment which does not normally leave a scar, but it can be painful. (See Patient Information Leaflet on Cryotherapy)

·    Surgical removal. This requires local injection into the affected skin with anaesthetic, 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.

·    Creams. Courses of creams containing drugs which may include 5-fluorouracil, imiquimod or Ingenol mebutate gel are useful treatments for actinic keratosis, especially if there are many of them. These preparations appear to selectively destroy the abnormal cells in sun-damaged skin. However, they often cause a lot of temporary inflammation of the treated areas. Diclofenac and retinoic acid are other drugs in cream or ointment form that are helpful when applied to milder actinic keratosis.

·    Photodynamic therapy. A special light activates a cream which has been applied to the affected area of skin. This treatment is only available in certain hospitals (see Patient Information Leaflet on Photodynamic Therapy).

·    Laser treatment may be useful particularly for actinic keratosis on the lips.

Self care (What can I do?)

Protecting your skin from the sun will reduce the number of new actinic keratosis you get, and also reduce the risk of getting a sun-induced skin cancer. You should be extra cautious in the sun by following these recommendations:

·    Protect yourself from the sun, from 11am to 3pm, especially in sunny weather.

·    Wear protective clothing – hats, long sleeves, long skirts or trousers.

·    Apply a sunscreen regularly, of sun protection factor 30 or above (and able to block both UVA and UVB light), to exposed skin before going into the sun, and re-apply according to the manufacturer’s recommendations, especially if sweating or after swimming, when you are out in the sun.

·    Protecting your children from the sun in the same way may reduce their risk of developing actinic keratosis.

·    Avoid artificial sunlamps, including sunbeds and UV tanning cabinets.

·    Examine your own skin every few months and see your doctor if an actinic keratosis starts to itch, bleed, or thicken, in case it has changed into a skin cancer (a squamous cell carcinoma).

Where can I find out more about actinic keratoses?

Web links to detailed leaflets:

www.skincarephysicians.com/actinickeratosesnet