Find out more about the possibilities of pharmaceutical marketing: http://www.cast-pharma.com/pharma-biotech-marketing-solutions/?ref=yt Connect with me on LinkedIn: http://www.linkedin.com/pub/stefan-wolf/6/31b/648 The very common skin disease actinic keratosis mainly affects the chest area, the head and neck, the arms and the back of the hands. Its lesions are mainly caused by chronic over-exposure to ultraviolet rays. They can have different degrees of severity and appear as dry, scaly, rough-textured lesions. In the skin cells, the highly energetic UV-B and UV-A rays damage the DNA. The resulting gene mutations can lead to an abnormal proliferation of epidermal keratinocytes in the epidermis and the typical signs of actinic keratosis. Untreated, the lesions may develop into more severe forms of actinic keratosis and even into an invasive squamous cell carcinoma.