What is a sunburn?

A sunburn is the burning, redness, or blistering of the skin caused by overexposure to the ultraviolet (UV) rays of the sun or a sunlamp. Most people have been sunburned many times. Vacations can quickly turn into painful experiences when the power of the sun is overlooked.

Unfortunately, the symptoms of sunburn do not begin until 2 to 4 hours after the sun's damage has been done. The peak reaction of redness, pain, and swelling is not seen for 24 hours. Minor sunburn is a first-degree burn which turns the skin pink or red. Prolonged sun exposure can cause blistering and a second-degree burn. Sunburn never causes a third-degree burn or scarring.

Repeated sun exposure and suntans cause premature aging of the skin (wrinkling, sagging, and brown sunspots). Repeated sunburns increase the risk of skin cancer in the damaged area. Each blistering sunburn doubles the risk of developing malignant melanoma, which is the most serious type of skin cancer.

How can I take care of myself?

• Pain relief

  The sensation of pain and heat will probably last 48 hours. Ibuprofen products (such as Advil) started early and continued for 2 days can greatly reduce the discomfort. Nonprescription 1% hydrocortisone cream or moisturizing creams applied three times a day may also reduce swelling and pain but only if the cream is used soon after you are sunburned. Continue using the hydrocortisone cream for 2 days. Do not use petroleum jelly or other ointments because they keep heat and sweat from escaping.

  The symptoms can also be helped by taking cool baths or putting cold wet cloths on the burned area several times a day. Showers are usually too painful.

  Drink extra water to replace the fluid lost into the swelling of sunburned skin and to prevent dehydration and dizziness.

  Peeling usually occurs in about a week. Put a moisturizing cream on your skin.

• Blisters

  If you have broken blisters, trim off the dead skin with small scissors. Then apply an antibiotic ointment (for example, bacitracin). Wash off and reapply the ointment twice a day for 3 days.

• Common mistakes in treatment and prevention of sunburn

  Avoid putting ointments or butter on a sunburn. They are painful to remove and not helpful.

  Don't buy any first aid creams or sprays for burns. They often contain benzocaine, which can cause an allergic rash.

  Don't confuse sunscreens, which block the sun's burning rays, with suntan lotions or oils, which mainly lubricate the skin.

How can I prevent sunburns?

Apply sunscreen any time you are going to be outdoors for more than 30 minutes per day. Wear a had with a brim.

• High-risk. About 15% of white teenagers have skin that never tans but only burns. These fair-skinned people need to be extremely careful about sun exposure throughout their lives. If you have red or blond hair, blue or green eyes, freckles, or excessive moles you are at increased risk for sunburn and skin cancer. Use a sunscreen throughout the summer, even for brief periods, and avoid the sun whenever possible.
• Tanning. Try to keep sun exposure to small amounts early in the season until a tan builds up. (Caution: While people with a suntan can tolerate a little more sun, they can still get a serious sunburn.) Start with 15 or 20 minutes of sun per day and increase by 5 minutes per day. Decrease daily exposure time if your skin becomes reddened. Because of the 2- to 4-hour delay before the symptoms of sunburn appear, don't expect symptoms (such as redness) to tell you when it's time to get out of the sun. After 1 hour of sun exposure, always apply a sunscreen.
• Time of day. Avoid exposure to the sun during the hours of 10:00 AM to 4:00 PM, when the sun's rays are most intense. Don't let overcast days give you a false sense of security. Over 70% of the sun's rays still get through the clouds. Over 30% of the sun's rays can also penetrate loosely woven fabrics (for example, a T-shirt).
• High altitude. Be especially careful about exposure to the sun at high altitudes. Sun exposure increases 4% for each 1000 feet of elevation above sea level. A sunburn can occur quickly when you are hiking above timberline. Remember also that water, sand, or snow increases sun exposure. The shade from a hat or umbrella won't protect you from reflected rays.
• Eyes, nose, and lips. Protect your eyes from the sun's rays. Years of exposure to ultraviolet light increases the risk of cataracts. Buy sunglasses with UV protection. To prevent sunburned lips, apply a lip coating that contains PABA. If your nose or some other area has been repeatedly burned during the summer, protect it completely from all the sun's rays with zinc oxide ointment.

The best way to prevent skin cancer is to prevent sunburn. Although skin cancer occurs in adults, it is caused by the sun exposure and sunburns that occurred during childhood and adolescence. Every time you protect yourself from too much sun exposure, you are helping prevent skin cancer.

Which kind of sunscreen should I use?

There are sunscreens on the market that prevent sunburn but still permit gradual tanning to occur. Choose a broad-spectrum sunscreen that screens out both UVA and UVB rays.

The sun protection factor (SPF) of sunscreen determines what percentage of the ultraviolet rays get through to the skin. An SPF of 15 allows only 1/15 (7%) of the sun's rays to get through. This allows sun of up to 5 hours without sunburning. An SPF higher than 15 protects against sunburn for more than 5 hours. However, an SPF higher than 15 is rarely needed because protection against sunburn for 5 hours is usually sufficient.

Fair-skinned people (with red or blond hair) need a sunscreen with an SPF of 30. The simplest approach is to use an SPF of 15 or greater for all other people.

Apply sunscreen 30 minutes before exposure to the sun to give it time to penetrate the skin. Give special attention to the areas most likely to become sunburned, such as your nose, ears, cheeks, and shoulders.

Most products need to be reapplied every 3 to 4 hours, as well as immediately after swimming or profuse sweating. A "waterproof" sunscreen stays on for about 30 minutes in water. Most people apply too little sunscreen. Use about the same amount as the amount of lotion you would put on dry skin.

When should I call my healthcare provider?

Call during office hours if:

• The sunburn looks infected (red streaks, yellow pus, etc.)
• You have other concerns or questions.