Background
Actinic keratosis (AK) is a visible result of sun damage to the skin, caused by exposure to UV radiation. AK is most often observed in people aged over 40. The lesions form on skin that has been exposed to the sun, and are usually red with small, hard scales or lumps. It is quite usual to have one or a few small AKs, but it is not uncommon for these to spread over the years, resulting in a large collection of AKs on the forehead, for example. Very often, actinic keratosis causes itching and irritation - and sometimes even open sores. These are generally not dangerous, but in isolated cases they can lead to the more serious condition of squamous cell cancer, which is a malignant skin cancer.
Treatment
AK is most commonly treated with cryosurgery, which involves freezing the affected area with liquid nitrogen. Photodynamic therapy is very effective, especially if numerous AKs are to be treated.