Overview of Actinic Keratosis
Actinic keratosis (AK) is the most common precancerous lesion of the skin. These lesions appear as red, blotchy patches, commonly found on the face and head. They occur much more frequently in older individuals with fair skin, blue eyes, and a history of freckling. As they are directly related to cumulative sun exposure, over 50 percent of fair-skinned people living in sunny climates develop these lesions. Consequently, reducing sun exposure throughout one's lifetime, particularly in childhood, can dramatically reduce the risk for actinic keratosis.
The term "precancer" implies that these lesions could develop into skin cancer. This is true of actinic keratosis. Progression to actual skin cancer does not occur in most cases of AK. In actinic keratosis, early malignant cells are detected, and because they have not extended through the entire epidermis, they are fairly easy to treat.
Actinic Keratosis Causes
Actinic keratoses are directly related to the amount of sun exposure one has had over a lifetime. The cumulative cell damage caused by sun exposure eventually causes mutations in the skin cell DNA, thus causing precancerous or cancerous lesions. Because fair-skinned people sunburn easily, they are at risk for AK.
Individuals that have received organ transplants and others with compromised immune systems have a much greater risk for developing AK. Certain genetic disorders result in increased sun sensitivity or decreased ability to repair cell damage. These individuals have a greater propensity for developing premalignancies and malignancies of the skin.