actinic keratosis

actinic keratosis (plural actinic keratoses)

1. (medicine, pathology, dermatology) A potentially precancerous skin lesion, typically on the upper portion of the head, characterized by discolored, thickened or scaly growths of keratin and caused by repeated exposure to ultraviolet light, such as from sunlight or tanning beds.
   • 2001, Steven M. Ruhoy, Alan R. Silverman, “26: Pathology of Selected Skin Lesions of the Head and Neck: II: Actinic Keratosis”, in Leon Barnes, editor, Surgical Pathology of the Head and Neck, volume 3, page 1797:

     Approximately 1:1000 actinic keratoses per year will develop into a squamous cell carcinoma (28). Risk factors for the development of actinic keratosis include ease of sunburning and cumulative sun exposure (30).

   • 2002, Randall C. Thomas, Leslie R. Fox, “Chapter 32: Tumors of the Skin and Subcutis”, in Wallace B. Morrison, editor, Cancer in Dogs and Cats: Medical and Surgical Management, page 472:

     The term actinic keratosis has traditionally been used in both human and veterinary literature; however solar keratosis is a more accurate term because these lesions are associated with chronic exposure to solar radiation. […] American Staffordshire terriers, beagles, basset hounds, bull terriers and dalmatians are reported to be at increased risk of developing actinic keratoses.

   • 2013, James G. Marks Jr., Jeffrey J. Miller, Lookingbill and Marks' Principles of Dermatology, 5th edition, page 43:

     Actinic keratoses occur in sun-exposed areas: the face, dorsum of the hands and forearms, neck, upper back, and chest. […] An actinic keratosis is rough, scaling, and ill marginated; it is often easier felt than seen.

• (skin lesion characterized by discolored, thickened growths of keratin): solar keratosis, senile keratosis