Actinic Keratosis

Actinic keratosis (also called solar keratosis or sunspots) is a common precancerous skin condition caused by excessive exposure to ultraviolet light.

What Is Skin Cancer?

Skin cancer, the abnormal growth of skin cells, most often develops on skin exposed to the sun. But this common form of cancer can also occur on areas of your skin not ordinarily exposed to sunlight.

There are three major types of skin cancer—basal cell carcinoma, squamous cell carcinoma, and melanoma.

Causes of Skin Cancer

Skin cancer begins in your skin’s top layer—the epidermis. The epidermis is a thin layer that provides a protective cover of skin cells that your body continually sheds. The epidermis contains three main types of cells:

  • Squamous cells: These lie just below the outer surface and function as the skin’s inner lining.
  • Basal cells: These produce new skin cells, and sit beneath the squamous cells.
  • Melanocytes: These produce melanin—the pigment that gives skin its normal color—and are located in the lower part of your epidermis. Melanocytes produce more melanin when you’re in the sun to help protect the deeper layers of your skin.

Where your skin cancer begins determines its type and your treatment options.

Much of the damage to DNA in skin cells results from ultraviolet, or UV, radiation found in sunlight and in the lights used in tanning beds. But sun exposure doesn’t explain skin cancers that develop on skin not ordinarily exposed to sunlight. This indicates that other factors may contribute to your risk of skin cancer, such as being exposed to toxic substances or having a condition that weakens your immune system.

Actinic Keratosis

Actinic keratosis blemishes are rough, dry, tan- or pink-colored and often appear on facial skin—near the eyes, or on the nose, ears, or lips—or on other parts of the body that receive intense sunlight, such as the backs of the hands. They are most common in fair-skinned, middle-aged, or elderly individuals, who may have a single lesion or many.

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actinic keratosis
actinic keratosis. DermNet / CC BY-NC-ND 

Actinic keratosis can lead to more serious invasive squamous cell carcinoma (SCC) if left untreated. It is estimated that 40%–60% of SCCs begin as actinic keratosis.

Treatments include cryotherapy (freezing); curettage (scraping); laser ablation; photodynamic therapy; and topical (skin-only) creams such as fluorouracil, diclofenac, and imiquimod. The choice of treatment depends on the location of the lesion, how many there are, and the preferences of the patient.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. What is skin cancer?

  2. Wessely A, Steeb T, Heppt F, et al. A critical appraisal of evidence- and consensus-based guidelines for actinic keratosis. Curr Oncol. 2021;28(1):950-960. doi:10.3390/curroncol28010093

  3. Skin Cancer Foundation. Squamous cell carcinoma: risk factors.

  4. Gutzmer R, Wiegand S, Kölbl O, Wermker K, Heppt M, Berking C. Actinic keratosis and cutaneous squamous cell carcinoma. Dtsch Arztebl Int. 2019;116(37):616–626. doi:10.3238/arztebl.2019.0616

By Timothy DiChiara, PhD
Timothy J. DiChiara, PhD, is a former research scientist and published writer specializing in oncology.