causes of actinic keratosis
Causes of actinic keratosis: 1  Excessive sun exposure. 2  Weak immune system, immune stress, or use of immunosuppressive drugs (such as with organ transplant patients). 3  Age. Older people are more affected.  Viral infection. It is likely that human papillomavirus is involved in the development of actinic 1  keratoses. Skin colour.