 Actinic theratosis. Actinic theratosis Alaska is a preaconsorous patch of thick, scaly, or crusty skin. These growths are more common in fair-skinned people and those who are frequently in the sun. They usually form when skin gets damaged by ultraviolet UV radiation from the sun or indoor tanning beds. Galaskas are considered potentially pre-cancerous, left untreated. They may turn into a type of cancer called squatmus cell skin cancer. Untreated lesions have up to a 20% risk of progression to squatmus cell carcinoma, so treatment by a dermatologist is recommended. Development of these growths occurs when skin is constantly exposed to the sun over time. They usually appear as thick, scaly, or crusty areas that often feel dry or rough. In fact, galaskas are often felt before they are seen, and the texture is often compared to said paper. They may be dark, light, tan, pink, red, the combination of all these, or have the same color as the surrounding skin. An actinic theratosis lesion commonly ranges between 2 and 6 mm in size but can grow to be a few centimeters in diameter. They often appear on sun exposed areas of the skin, such as the face, ears, neck, scalp, chest, backs of hands, forearms, or lips. Because they are related to sun damage on the skin, most people who have an alexica have more than one. Often, large areas of sun exposed skin are diagnosed with a continuum of multiple clinically visible alexicas of different sizes and severities, typically accompanied by subclinical lesions that become apparent only in biopsies. This concept of a skin area showing multiple alexicas is termed field cancerization. Diagnosis is suspected clinically on physical exam, but can be confirmed by looking at cells from the lesion under a microscope. Different therapeutic options for Alaska are available. Photodynamic therapy PDT is recommended for the treatment of multiple alexic lesions and field cancerization. It involves the application of a photosensitizer to the skin followed by illumination with a strong light source. Topical creams may require daily application to affected skin areas over longer time periods. Cryotherapy is frequently used for single lesions, but undesired hypopigmentation may occur at the treatment site. By following up with a dermatologist, alexicas can be treated before they turn into skin cancer. If skin cancer does develop from an alexic lesion, it can be caught early with close monitoring, at a time when treatment can be curative.