Actinic keratoses

Also called Solar keratoses, Sun damage, Bowen's disease

Rough scaly patches from years of sun. Individually harmless, collectively a warning, and a small number turn into skin cancer.

What it is

Rough, scaly patches on skin that has had a lot of sun over a lifetime: the scalp in balding men, the face, ears, backs of the hands and forearms, and the lower legs in women.

They are very common over 60, and each individual one has only a small chance of becoming a squamous cell skin cancer. But somebody with many of them has a lot of sun-damaged skin, and their overall risk of skin cancer is meaningfully raised. That is the useful way to read them: not a set of individual threats but a field of damage that needs watching.

Bowen's disease is a related and more advanced change, an early skin cancer confined to the top layer of skin, usually appearing as a persistent red scaly patch, often on the lower leg. It is treatable and needs treating.

The transformation to invasive cancer is signalled by change: thickening, becoming lumpy or tender, ulcerating or bleeding. Those are the features to report.

Risk is much higher in people who are immunosuppressed, particularly organ transplant recipients, who need regular dermatology review.

Signs you might notice

Rough, dry, scaly patches, often easier to feel than to see, like fine sandpaper.

Pink, red, brown or skin-coloured, sometimes with a yellowish crust.

A few millimetres to a couple of centimetres across, often several together.

Sometimes itchy or tender, or catching on clothing.

Bowen's disease: a persistent red, scaly, flat patch that slowly enlarges, often mistaken for eczema or psoriasis and not responding to steroid cream.

Report promptly: a patch that becomes thick, lumpy or hard; one that bleeds, ulcerates or will not heal; one that becomes painful; or any rapidly growing lump. See non-melanoma skin cancer and melanoma.

How it can affect day-to-day life

These are the marks of a working life spent outdoors, and they arrive decades after the exposure that caused them. Farmers, builders, gardeners, sailors and roofers are the classic group, and none of them were told at the time.

Treatment creams work by causing an inflammatory reaction, so the skin looks dramatically worse before it looks better, for several weeks. People stop because they think something has gone wrong. Being warned, with a photograph of what to expect, is what gets courses completed.

Scalp lesions in men who have lost their hair are easy to miss and hard to see. Somebody else needs to look.

For older people who cannot see or reach their own back, legs and scalp, the person providing personal care is the one who will notice a change.

Supporting someone well

Get any new, changing, bleeding or non-healing patch looked at rather than watched.

Complete the treatment course. The redness and crusting is the treatment working, not a reaction to stop for.

Sun protection from now on genuinely reduces new lesions: factor 30 or above daily on the face, ears, scalp and hands, a hat, and shade in the middle of the day.

Look at the scalp, ears, backs of hands and lower legs during personal care, and photograph anything being watched so change is measurable.

For anybody immunosuppressed or transplanted, ask for regular dermatology review; the risk is very different in that group.

Do not use steroid cream long term on a scaly patch that is not responding. Ask whether it is Bowen's disease.

Where to get help

A GP practice, which can treat most actinic keratoses and refer where needed.

Urgent referral for a lesion that is thickening, ulcerating, bleeding or growing.

British Association of Dermatologists publish patient leaflets on actinic keratoses and Bowen's disease.

British Skin Foundation for general skin health information.