Actinic Keratosis (Solar Keratosis)

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Medical Author:

Alan Rockoff, MD

Alan Rockoff, MD

Dr. Rockoff received his undergraduate degree from Yeshiva College with the distinction of Summa Cum Laude. He received his medical degree from the Albert Einstein College of Medicine. His internship and two years of Pediatric residency were at the Bronx Municipal Hospital Center, followed by training in Dermatology at the combined residency program at Tufts and Boston Universities. Dr. Rockoff is certified by both the American Board of Dermatology and the American Board of Pediatrics.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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An actinic keratosis (AK), also known as a solar keratosis, is a small, rough spot occurring on skin that has been chronically exposed to the sun. Actinic keratoses generally measure in size between 2-6 millimeters in diameter (between the size of a pencil point and that of an eraser). They are usually reddish in color, with a rough texture and often have a white or yellowish scale on top. Actinic keratosis often occurs against a background of sun damage, including sallowness, wrinkles, and superficial blood vessels.

In addition to feeling rough, actinic keratoses may feel sore or painful when fingers or clothing rub against them.

Specialized forms of actinic keratoses include cutaneous horns, in which the skin protrudes in a thick, hornlike manner, and actinic cheilitis, which refers to scaling and roughness of the lower lip and blurring of the border of the lip and adjacent skin.

Those who develop actinic keratoses tend to be fair-skinned people who have spent a lot of time outdoors at work or at play over the course of many years or who have exposed their skin to indoor tanning. Their skin often becomes wrinkled, mottled, and discolored from sun exposure. Others at risk for developing actinic keratoses include those who have their immune systems suppressed, such as organ transplant patients, as well as patients with psoriasis treated with PUVA therapy (topical long-wave ultraviolet light plus oral chemicals called psoralens.)