Keratosis is a disease characterized by an overgrowth of horny tissue or tissue containing a protein called keratin. There are several different types of keratosis with varying degrees of severity including actinic keratosis, keratosis pilaris, hyperkeratosis, seborrheic keratosis and keratosis follicularis. The most common type of keratosis affecting the scalp is actinic keratosis.
Actinic keratosis is also called solar keratosis because it results from frequent or high-level exposure to ultraviolet radiation. In a healthy body, new epithelial or skin cells are constantly generated which replace old cells and provide a formidable defense against the outside environment. When the skin is damaged by UV radiation, lesions form and the skin becomes discolored.
Actinic keratoses often begin as very small bumps which are identified by their "sandpaper" quality. Early on, the bumps may disappear and reappear. The keratoses come in a variety of colors including pink, tan, red and skin color. Over time, the keratoses develop into scaly or crusty lesions on the scalp, face, forearms, hands, shoulders, neck and other areas of the body.
Actinic keratoses are called "pre-cancers" because they have the potential to develop into a squamous cell carcinoma. About 2 to 10 percent of squamous cell carcinomas spread to internal organs and become life-threatening. According to the Skin Cancer Foundation, up to 10 percent of keratoses are malignant or dangerous and harmful. However, if caught and treated early on actinic keratoses can be eliminated before they have the opportunity become cancerous.
Since it is impossible to determine which keratoses will become cancerous, all lesions must be removed. Your dermatologist will have several options available for removing the keratoses including freezing or cryotherapy, chemotherapeutic creams, chemical peels, scraping or cutterage, dermabrasion and laser therapy. Of course, the best treatment is prevention. Actinic keratosis can be prevented by wearing sunscreen outdoors and by avoiding tanning booths.