Actinic keratosis [1]

Sun-Damaged Skin

What Is It?

Although most people love the warmth and light of the sun, too much sun exposure can cause significant damage to human skin. Over time, the sun’s heat tends to dry out areas of unprotected skin and to deplete the skin’s supply of natural lubricating oils. In addition, the sun’s ultraviolet (UV) radiation can cause both short-term burning and long-term changes in the skin’s structure.

The most common types of sun damage to the skin are:

 

 

  • Dry skin — Sun-exposed skin can gradually lose moisture and essential oils, making it appear dry, flaky and prematurely wrinkled, even in younger people.


  • Sunburn — Sunburn is the common name for the short-term skin damage caused by UV radiation. Mild sunburn causes only painful reddening of the skin, but more severe cases can produce tiny fluid-filled bumps (vesicles) or larger blisters.


  • Actinic keratosis — This is a small, scaly patch of sun-damaged skin that has a pink, red, yellow or brownish tint. Unlike suntan markings or sunburns, an actinic keratosis does not go away. It develops in areas of skin that have undergone repeated or long-term exposure to the sun’s UV light, and it is a warning sign of increased risk of skin cancer. About one in every 400 patches of actinic keratosis evolves into a squamous cell cancer of the skin.


  • Long-term changes in the skin’s collagen (a structural protein) — These changes include photoaging (premature aging of the skin because of sun exposure) and senile purpura (increased fragility of the skin’s blood vessels due to a combination of aging and sun exposure). In photoaging, the skin develops wrinkles and fine lines because of UV-related changes in the collagen of a deep layer of the skin called the dermis. In senile purpura, UV radiation damages the structural collagen that supports the walls of the skin’s tiny blood vessels. This makes blood vessels more fragile and more liable to rupture following a slight impact.

Over a lifetime, repeated episodes of sunburn and unprotected sun exposure also can increase a person’s risk for malignant melanoma and other forms of skin cancer. As a rule, if you have fair skin and light eyes, you are at greater risk of sun-related skin damage and skin cancers. This is because your skin contains less of a brown pigment called melanin, which helps to protect the skin from the effects of UV radiation.

Symptoms

Sun-damaged skin shows the following symptoms:

  • Dry skin — The skin appears dry, flaky and slightly more wrinkled than skin on other parts of your body that have not been exposed to the sun. Dry skin is also one of the most common causes of itching.


  • Sunburn — Mild sunburn causes pain and redness on sun-exposed skin. In most cases, there are clear boundary lines where the skin has been protected from the sun by shirt sleeves, shorts, a bathing suit or other clothing. More severe cases of sunburn produce painful blisters, sometimes together with nausea and dizziness.


  • Actinic keratosis — An actinic keratosis appears as a persistent patch of scaly skin that has a pink, yellow, red or brownish tint. Rarely, the patch may itch or be slightly tender.


  • Long-term changes in the skin’s collagen — Symptoms of collagen changes include fine lines, deeper wrinkles, a thickened skin texture, and in senile purpura, easy bruising on sun-exposed areas, especially the back of the hands and forearms.

Diagnosis

In most cases, your doctor can confirm that you have sun-damaged skin simply by examining the area. Rarely, a biopsy may be necessary to rule out skin cancer in a patch of actinic keratosis.

Expected Duration

The painful redness of sunburn tends to fade within a few days, provided that you do not re-expose your injured skin to the sun without using a sunblock or sunscreen. Other forms of sun damage tend to be long-term conditions, although prescription medications, nonprescription remedies and skin-resurfacing treatments may improve the skin’s appearance.

Prevention

You can help 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 of 15 or above, with a broad spectrum of protection against both UV-A and UV-B rays.


  • 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 for 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 provider 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 multiple actinic keratoses should have their skin checked by a doctor once a year.

Treatment

The type of treatment depends on the form of sun damage:

  • Dry skin — Try using a moisturizer that contains at least one of the following ingredients: glycerin, urea, pyroglutamic acid, sorbitol, lactic acid, lactate salts or alpha-hydroxy acids. Avoid using alpha-hydroxy acids or other acids on any sunburned skin. Avoid hot baths or hot showers, because these can make your sun-damaged skin even drier. Wash only with warm or cool water, using soap that either has a high fat content or contains glycerin.


  • Sunburn — For painful sunburn, try applying cool compresses to your injured skin, or mist the area with sprays of cool water. If your discomfort continues, take a nonprescription pain medication such as ibuprofen (Advil, Motrin) or aspirin. Your doctor may prescribe stronger anti-inflammatory medication if you have an extensive sunburn with severe blistering and pain.


  • Actinic keratosis — The type of treatment that will work best for you depends on many factors, including the number, size and location of your actinic keratoses. Options include:
    • Watchful waiting — There is no immediate treatment, but the doctor regularly monitors the area of abnormal skin.
    • Topical fluorouracil — The anticancer drug 5-fluorouracil (5-FU) is applied directly to the skin to eliminate the actinic keratosis.
    • Cryotherapy — The actinic keratosis is frozen with liquid nitrogen.
    • Chemical peels — A strong chemical solution is used to remove the top layer of skin, which later regrows.
    • Laser resurfacing — This works in the same way as a chemical peel, but it uses a laser beam instead of a chemical solution.
    • Shave excision — The doctor carefully shaves away the area of abnormal skin. If necessary, the skin shavings can be used as a biopsy specimen to check for cancer.

    Also, because an actinic keratosis is a sign that you are at increased risk of skin cancer, your doctor will schedule regular follow-up skin examinations to check periodically for new areas of abnormal skin.


  • Photoaging and other collagen changes — Although it is not possible to reverse all of the effects of long-term sun damage, your doctor may be able to improve the appearance of your skin by prescribing tretinoin (a derivative of vitamin A) or strong alpha-hydroxy acids that you can apply directly to the skin. Other options include chemical peels, cryosurgery, laser resurfacing or dermabrasion, in which the outer layer of skin is rubbed away with a special rotating brush or wheel. Injections of botulinum toxin (Botox) to temporarily reduce wrinkles have become popular as a salon treatment, but the long-term safety of their repeated use is not known.

When To Call A Professional

Call your primary care physician or a dermatologist (a doctor who specializes in skin problems) if you have any of the following problems:

  • Dry skin that doesn’t respond to nonprescription treatments
  • A severe case of blistering sunburn
  • A milder sunburn over a very large portion of your skin, especially if your painful skin makes it hard for you to sleep or to wear clothing
  • An abnormal scaly patch or nodule anywhere on your skin, or a skin ulcer that does not heal
  • Abnormal bleeding under the skin, or skin that bruises very easily

Prognosis

Cosmetically, the prognosis is excellent for most skin problems resulting from sun exposure. Most treatments for an actinic keratosis can leave a pale (de-pigmented) area of the skin surface. More important than appearance, however, is the long-term impact of sun damage on your chances of developing skin cancer. Overall, the greater the amount of unprotected sun exposure you have during your lifetime, the greater your risk of skin cancer, especially if you have a light complexion.

 

Johns Hopkins patient information

Last revised: December 5, 2012
by Potos A. Aagen, M.D.

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