Chronic Effects of Sunlight

ByJulia Benedetti, MD, Harvard Medical School
Reviewed/Revised Oct 2023
View Patient Education

Chronic affects of sunlight include photoaging, actinic keratoses, and skin cancer. (See also Overview of Effects of Sunlight.)

Skincare and Aging Myths
podcast

Photoaging

Chronic exposure to sunlight ages the skin (photoaging, dermatoheliosis, extrinsic aging), primarily by causing destruction of skin collagen due to various biochemical and DNA disruptions. Skin changes include both fine and coarse wrinkles, rough leathery texture, mottled pigmentation, lentigines (large frecklelike spots), sallowness, and telangiectasia.

Photoaging
Hide Details
Photoaged skin is characterized by fine and coarse wrinkling, irregular mottled pigmentation, lentigines (large frecklelike spots), roughness, and sallowness.
Image provided by Barbara A. Gilchrest, MD.

Actinic keratoses

Actinic keratoses are precancerous changes in skin cells (keratinocytes) that are a frequent consequence of many years of sun exposure. Actinic keratoses may be pink, red, or, less commonly, gray or brown, and may feel rough and scaly.

Seborrheic keratoses look similar to actinic keratoses. They may appear on areas of the skin that are not exposed to sunlight and are not precancerous.

Skin cancers

The incidence of squamous cell carcinoma and basal cell carcinoma in fair, light-skinned people is directly proportional to the total annual sunlight in the area. Such lesions are especially common among people who were extensively exposed to sunlight as children and adolescents and among those who are chronically exposed to the sun as part of their profession or recreational activities (eg, athletes, farmers, ranchers, sailors, frequent sunbathers). Sun exposure also substantially increases the risk of malignant melanoma.

Treating Chronic Effects of Sunlight

  • Minimization of UV light exposure

  • Topical treatments for photoaged skin

Treatment begins with preventive efforts to minimize UV light exposure—avoiding the sun and tanning beds and wearing protective clothing and sunscreen.

Photoaging

Actinic keratoses

For treatment of actinic keratoses, see Actinic Keratoses.

Skin cancers

For treatment of skin cancers, see Cancers of the Skin.

Drugs Mentioned In This Article
quizzes_lightbulb_red
Test your KnowledgeTake a Quiz!
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID