Actinic keratoses are evidence of previous sun damage to the skin causing the top layer of the skin to become thickened and scaly. Actinic keratoses are extremely common on sun exposed skin sites, i.e the face, forearms and lower legs particularly those people who normally do not tan very easily. They are not infectious or cancerous.
There is a very small chance of an actinic keratosis changing into a skin tumour (probably less than 1 in 1000). If this were to happen the otherwise flat and scaly lesion would become much more raised, crustier and larger.
Actinic keratoses can be treated by freezing, scraping, surgical removal or by the use of a special cream. If they are not troublesome, however, the doctor may decide that they do not need any treatment.
Actinic keratoses are caused by cumulative sun exposure over many years (from sunbathing, sunbed use, 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.
They can be improved and may even disappear if further sun exposure is reduced by avoiding the sun or protecting the skin by wearing appropriate clothing. Sunscreens may also help on sites that cannot be covered by clothing. If a sunscreen is used a total block (high sun protection factor and a 4 star UVA rating) is preferred.
Useful websites:
http://www.bad.org.uk/for-the-public/patient-information-leaflets
