What is solar keratosis?

What is solar keratosis?

Solar keratosis is the commonest skin condition resulting from sun-damaged skin2.

A solar keratosis is a rough or scaly area of skin that is caused by repeated sun damage over many years3. The ultraviolet (UV) radiation from the sun causes skin cells to divide and grow abnormally, which changes the size, shape, structure and organisation of the skin cells affected.

Picture examples of Typical Solar Keratosis

Solar keratosis causes the skin to feel rough and dry, so it is often recognised more by touch than appearance. Many people with solar keratoses are not aware of them at all, but the affected area of skin may itch or feel prickly or tender, particularly after being in the sun2.

A solar keratosis can remain the same colour as the rest of the skin, but it frequently becomes pink, red or brown, giving a blotchy appearance if a person has a lot of solar keratoses3.

Solar keratoses are found mainly on areas of the skin that are exposed to sun – particularly the backs of the hands and forearms, the face (including the lips and ears), the scalp in men who are going ‘thin on top’ and the lower legs in women3.  

Another name for solar keratosis is actinic ketatosis (or AK, for short) – which is the term often used by doctors


What does solar keratosis look like?

Solar keratoses come in lots of different shapes, colours and sizes – and can differ from one another even in a single individual. They can be hard to see at first, and may be easier to feel – being rough, like sandpaper. But they can grow over time, up to a centimetre or two in diameter3.

In colour, solar keratoses can be skin coloured, but they can be pink, red or brown3.

In shape, solar keratoses can become raised, hard and warty. Some may even develop a small horn-shaped outgrowth3.

The skin surrounding a solar keratosis can also be affected, and often looks sun-damaged: blotchy, freckled and wrinkled3.


How common are solar keratoses?

Solar keratoses are very common, particularly as people get older – although they can develop at any age. They are about twice as common in men than in women, and occur in more than one-third of men and in just under one in five women over the age of 70 years in the UK4.

Unfortunately, solar keratoses are becoming more common5


What is the risk?

Solar keratoses are usually harmless but there is a small risk of some lesions progressing to a type of skin cancer called squamous cell carcinoma3. They can be seen as an early step on the way to squamous cell carcinoma – so are precancerous lesions - although not all solar keratoses become cancerous5.  

Estimates vary as to how often solar keratoses develop into skin cancer, but it’s thought to occur in about one in every 50 people who develop them4.  The risk of progressing to cancer is higher in people who have a weakened immune system4. It also increases with the number of solar keratoses – the more you have, the higher the risk5.


When to see your doctor

Solar keratoses often cause little trouble, but if one starts to grow into a lump, becomes itchy or tender or bleeds, then see your doctor. These changes may mean that the solar keratosis is developing into a skin cancer3.  

Early diagnosis and treatment can reduce the risk of solar keratosis progressing into a skin cancer3.

Solar keratoses are not contagious, or catching, so other people won’t be at risk if they touch your skin lesions3.