Go to AAD Home
Donate For AAD Members Search

Go to AAD Home

Actinic keratosis: Who gets and causes

An actinic keratosis (AK) is a precancerous skin growth that develops on skin that’s been badly damaged by ultraviolet (UV) light from:

  • The sun

  • Indoor tanning equipment, such as tanning beds or sunlamps

How can UV light cause actinic keratosis?

When UV light hits our skin, it can damage cells in the skin called keratinocytes. These cells live in the outermost layer of the skin and give our skin its texture. When UV light damages these cells, changes occur that cause our skin to:

  • Feel rough and scaly

  • Appear discolored

  • Develop bumps and horn-like growths

These are signs of AKs.

Do some people have a higher risk of developing actinic keratosis?

Yes, the people most likely to get AKs have certain risk factors. A risk factor is anything that increases your risk of developing a disease.

The risk factors for AKs are:

  • Fair skin (burns easily and rarely tans)

  • Naturally red or blond hair

  • Light-colored eyes

  • Sun exposure (seldom protected your skin from the sun)

  • 50 years of age or older

  • Tanning bed use

  • Organ transplant recipient

  • Weakened immune system

  • Albino skin

  • Xeroderma pigmentosum, Rothnord-Thomson syndrome, or Bloom syndrome

Most people who get AKs have spent a lot of time outdoors without protecting their skin from the sun and are now 50 years of age or older.

Most people who get actinic keratosis have spent a lot of time outdoors without protection from the sun

The people most likely to develop precancerous skin growths on their skin have fair skin, light-colored eyes, and signs of sun damage that show they rarely protected their skin from the sun over the years.

Cheerful senior woman embracing senior man from behind at the park

If you used tanning beds or lived in a region that is warm and sunny year-round, you may develop AKs at a younger age. AKs can appear in your 20s or earlier.

Anyone who has received a transplanted organ tends to develop many AKs. The medication you take to prevent your body from rejecting the transplanted organ suppresses your immune system so greatly that your body has difficulty healing any damage caused the sun’s UV light. This causes AKs to develop more quickly.

If you notice a rough patch on your skin or a chapped lip that won’t heal, dermatologists recommend that you have it examined. Left untreated, some AKs turn into a type of skin cancer called squamous cell carcinoma.

To find out how dermatologists diagnose and treat AKs, go to, Actinic keratosis: Diagnosis and treatment.

Getty Images

Duncan KO, Geisse JK, et al. “Epithelial precancerous lesions.” In: Wolff K, Goldsmith LA, et al. Fitzpatrick’s Dermatology in General Medicine (seventh edition). McGraw Hill Medical, New York, 2008: 1007-15.

Rosen T, Lebwohl MG. “Prevalence and awareness of actinic keratosis: Barriers and opportunities.” J Am Acad Dermatol 2013;68:S2-9.