Actinic Keratosis (also known as solar keratosis)
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 do not normally 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 excessive sun exposure.
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 (at least factor 15) is preferred.