Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Sun-Damaged Skin (Actinic keratosis)

Prevention

You can help to prevent sun-damaged skin by taking the following steps:

• Apply a sunscreen before you go outdoors. Choose a sunscreen that has a sun protection factor (SPF) of 15 or above, with a broad spectrum of protection against both UV-A and UV-B rays. Be sure to reapply often to avoid sweating off or washing off the sunscreen.

• Use a sunblock on your lips. Choose a product that has been specially formulated for the lips, with a sun protection factor of 20 or more.

• Limit your time outdoors when the sun is at its peak (from about 10 a.m. to 3 p.m. in most parts of the continental United States).

• Wear sunglasses with UV light protection.

• Wear long pants, a shirt with long sleeves and a hat with a wide brim.

• Be aware that some medicines and skin care products can increase your skin's risk of UV damage. These include certain antibiotics, as well as some prescription medicines that are used to treat psychiatric illness, high blood pressure, heart failure, acne and allergies. If you are taking a prescription medication and you normally spend a great deal of time outdoors, ask your health care professional whether you should take any special precautions to avoid sun exposure. Also, be aware that certain nonprescription skin care products containing alpha-hydroxy acids can make your skin more vulnerable to damage from sunlight.

To help detect actinic keratoses and other skin abnormalities in their earliest stages, examine your entire skin surface thoroughly every one to two months. Check for patches of discolored or scaly skin, moles, small pearly nodules, sores and other skin abnormalities on all parts of your body, including your scalp and genitals. Use a mirror to inspect harder-to-see areas of your back, shoulders, upper arms, buttocks and the soles of your feet. People who have numerous actinic keratoses should have their skin checked by a doctor at least twice a year.