Wiktionary
n. (context medicine English) A lesion on the skin, typically on the upper portion of the head, characterized by discolored, thickened or scaly growths of keratin, caused by exposure to the sun; common in fair-complected people of a certain age. They are precancerous.
WordNet
n. an overgrowth of skin layers resulting from extended exposure to the sun
Wikipedia
Actinic keratosis (also called "solar keratosis" and "senile keratosis"; abbreviated as "AK") is a pre-cancerous 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. AKs are considered potentially pre-cancerous; left untreated, they may turn into a type of cancer called squamous cell carcinoma. Untreated lesions have up to a 20% risk of progression to squamous 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, AKs are often felt before they are seen, and the texture is often compared to sandpaper. They may be dark, light, tan, pink, red, a combination of all these, or have the same color as the surrounding skin. An actinic keratosis lesion commonly ranges between 2 and 6 millimeters 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 AK have more than one. Often, large areas of sun-exposed skin are diagnosed with a continuum of multiple clinically visible AKs of different sizes and severities, typically accompanied by subclinical lesions that become apparent only in biopsies. This concept of a skin area showing multiple AKs 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 AK are available. Photodynamic therapy (PDT) is recommended for the treatment of multiple AK 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, AKs can be treated before they turn into skin cancer. If skin cancer does develop from an AK lesion, it can be caught early with close monitoring, at a time when treatment can be curative.
Usage examples of "actinic keratosis".
He had never been to the hospital and only once sought medical carefor actinic keratosis, a condition besetting fair-skinned Scandinavians, which had been remedied with the removal of a few frecklelike papules on his forehead and nose, the consequence of too much sun as an adolescent.