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Actinic Keratosis

Published on June 5, 2024 at 8:00 / Updated on June 21, 2024 at 8:01

Actinic keratoses are lesions that form on the skin's surface.


The lesions are caused by long-term, cumulative sun exposure. Sunlight damages the epidermal skin cells (the superficial or outermost layer of the skin), causing them to develop abnormally.

Persons most at risk

Individuals with fair skin (blonds, redheads), who do not tan, who burn when out in the sun, who work outdoors, as well as the elderly, are at a higher risk of developing actinic keratoses.


Actinic keratosis lesions develop in areas that have been frequently exposed to sun, especially the face. These lesions are:

  • reddish to brownish in colour
  • rough
  • scaly
  • flat or raised
  • 3 to 10 mm in diameter
  • sometimes itchy or accompanied by a burning sensation

Over time, they can grow, thicken and harden. In some cases, they can develop into conical horny outgrowths.


A physician will usually be able to diagnose actinic keratosis during a skin examination. Occasionally, a biopsy, which involves taking a sample of the affected skin, is ordered for a more in-depth analysis.


These lesions can reach the deeper layers of the skin (the dermis) and can develop into skin cancer. It is therefore important to treat the lesions in order to prevent them for causing further damage.


Treatment is based on the size, location and number of lesions, as well as the person's overall health. There are several treatment methods, all of which can be performed in the physician's office, or at home. Home treatment involves the application of creams over several weeks.


The most simple and effective way to prevent actinic keratosis is to protect your skin from the sun's harmful rays. You can do so by applying sunscreen with a minimum SPF of 15, and by wearing long sleeved shirts and pants as well as wide-brimmed hats when the sun's rays are at their most intense. It is also recommended that you avoid being in the sun when the rays are at their strongest (between 10 a.m. and 4 p.m.).

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