About the sun
The sun produces invisible rays called ultraviolet-A (UVA) and ultraviolet-B (UVB). These rays can cause sunburn, suntan, and sun damage to the skin. In addition, too much sun can cause sunburn, skin texture changes, and skin cancers. Rash problems also can be attributed to sunlight. Even on cloudy days, UV radiation reaches the earth and can cause skin damage.
What is sunburn?
Sunburn is a condition that occurs when the amount of exposure to the sun or another ultraviolet light source exceeds the ability of the body's protective pigment (melanin) to protect the skin.
When the skin is burned, sunburn is not immediately apparent. By the time the skin starts to become painful and red, the damage has been done. The pain of sunburn is most severe between six and 48 hours after sun exposure.
What are the symptoms of sunburn?
Symptoms of sunburn include painful, reddened skin. Severe sunburn might result in swelling and blisters. People who are severely sunburned might develop a fever, chills, and/or weakness. In rare cases, people with sunburn can go into shock.
Several days after sunburn, people with naturally fair skin might have peeling in the burned areas. Some itching might occur and the peeled areas are even more sensitive to sunburn for several weeks.
How is sunburn treated?
The following can help ease the discomfort of sunburn:
- Apply cold compress to the affected area(s).
- Take aspirin or acetaminophen to relieve discomfort and inflammation.
- Use a cooling gel or ointment containing aloe vera.
In cases of severe sunburn or sunstroke, see your doctor immediately.
What is photosensitivity?
Most people’s skin will burn if there is enough exposure to UV radiation. However, some people burn particularly easily or develop exaggerated skin reactions to sunlight. This condition is called photosensitivity. People often call this a sun allergy.
People with photosensitivity have an immunological response to light--most often sunlight. They can break out in a rash when exposed to sunlight. The amount of exposure required to cause a reaction varies from person to person. Some people with photosensitivity are also affected by indoor fluorescent lighting.
What are the symptoms of photosensitivity?
Symptoms might include a pink or red skin rash with blotchy blisters, scaly patches, or raised spots on areas directly exposed to the sun. Itching and burning might occur, and the rash might last for several days. In some people, the reaction to sunlight gradually lessens with subsequent exposures.
What causes photosensitivity?
Photosensitivity has been linked to the following:
- Contact with chemicals, fragrances, or plants
- Medicines (including sulfonamides, tetracycline, and thiazide diuretics) that are taken internally
- Herbs including St John’s Wort
- Autoimmune diseases such as lupus erythematosus
- Porphyria, a metabolic disorder that is usually hereditary
How is photosensitivity treated?
Some types of photosensitivity might respond to specific treatments such as oral beta-carotene, steroids, or other medicines.
What is polymorphous light eruption?
Polymorphic light eruption (PMLE) is a condition in which skin rashes can develop after fairly limited sun exposure. PMLE usually affects females between the ages of 20 and 40. The condition also can affect children, but rarely affects men. PMLE is more common in places where sun exposure is not common.
What are the symptoms of PMLE?
The term 'polymorphic' refers to the fact that the rash can take many forms. A common kind of PMLE resembles groups of pink or red raised spots on the arms. Other areas, including the legs and chest, also might be affected. Sometimes the rash has blisters and larger dry, red patches. The rash is accompanied by a burning or itching that can last for several days.
How is PMLE treated?
In severe cases of PMLE, a doctor might recommend oral steroids or beta carotene. Hydroxychloroquine, a medicine used to treat skin conditions, sometimes is recommended.
Protecting skin from the sun
Protecting your skin from the sun can help you prevent skin damage. To protect your skin from the sun, you can do the following:
- Avoid the sun during peak hours (usually 10 a.m. to 4 p.m.).
- Dress sensibly. The tighter the weave of the clothing, the more sun protection it will offer. Wear a wide-brimmed hat and sunglasses.
- Avoid deliberate sunbathing.
- Use a sunscreen even on cloudy days. Sunscreens should be applied about 20 minutes before going outdoors. Even water-resistant sunscreens should be reapplied about every two hours, after swimming, or after strenuous activity.
Choosing a sunscreen
Different sunscreens are appropriate for different people. For children under six months old, the best option is to keep them out of the sun if possible. For young children, "physical" sun blocks that are made with zinc oxide or titanium dioxide are preferable to chemical sunscreens as the latter might cause allergic reactions because the skin absorbs the active ingredients. Zinc oxide and titanium dioxide are not absorbed into the skin. If a chemical sun block is used for children, it should have a minimum SPF of 15.
Pregnant women are especially sun-sensitive because of increased estrogen levels that stimulate the production of melanin. Pregnant women should use a sunscreen with an SPF of at least 30. Dermatologists also advise pregnant women sit under an umbrella or in the shade when outdoors for long periods.
People with dark skin would benefit from sunscreen with an SPF of 8, unless they are in the sun for long periods of time. If so, a sunscreen with an SPF 15 or higher is recommended. Sunscreens with SPF numbers that are higher than 15 might benefit people who want to minimize their exposure to the sun, especially people who are fair-skinned.
When choosing a chemical sunscreen, try to find one that labeled "PABA-free." PABA is a chemical that is associated with skin irritation. Skin irritations can result from various sunscreen ingredients, so testing the sunscreen on a small potion of the skin before use is a good idea.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 3/7/2005
