Patient information: Sunburn prevention

OVERVIEW

There are a number of effective ways to prevent sunburn, including staying out of the sun during peak hours, sunscreen, and protective clothing. While these measures are important for everyone, they are especially important for children and people with fair skin.

This article discusses ways to prevent sunburn. The treatment of sunburn is discussed separately. (See "Patient information: Sunburn".) More detailed information about sunburn is available by subscription. (See "Sunburn".)

AVOID SUN EXPOSURE

It is important to prepare for sun exposure, especially if you plan to be out in the sun for an extended period of time or during the middle of the day, when the sun's rays are strongest (10:00 AM to 4:00 PM during daylight savings time in the continental United States).

Even on cloudy days, it is important to protect your skin because UV radiation can pass through the clouds and cause sunburn. In addition, UV rays can be reflected off of surfaces like sand, snow, cement, and water. Using two types of protection (shade/clothing plus sunscreen) is the best way to reduce sun exposure.

Seek shade — Areas that are shaded receive less UV radiation, and can reduce your chances of developing a sunburn. Trees, an umbrella, or a structure (eg, porch, tent) can help to provide shade. Sunscreen is still recommended while sitting in the shade because your skin is exposed to some UV rays, even in the shade.

UV index — The UV index was developed to predict the risk of sunburn in your area on a given day based upon the weather conditions. It gives a number between zero and 10, where zero indicates a low risk of sun exposure and 10 indicates a very high risk of exposure. You can find information about the UV index online at www.epa.gov/sunwise/uvindex.html or by calling 1-800-296-1996.

SUNSCREEN

There are a wide variety of sun-blocking agents (sunscreens) available to protect your skin from sunburn, including gels, lotions, sprays, and ointments. Sunscreen protects the skin by absorbing or reflecting UV radiation. The Sun Protection Factor (SPF) is an indicator of how much protection the sunscreen offers against UVB (sunburn) rays. You should look for a sunscreen that is labeled as broad-spectrum, meaning it protects against both UVA and UVB rays.

What SPF is best? — Most healthcare providers, as well as the American Academy of Dermatology, recommend the following:

• Use a sunscreen with an SPF of 30 or greater on exposed skin every day.
• Use a sunscreen that protects against both UVA and UVB radiation.
• You may need a higher SPF if you are fair-skinned, if you will be in the sun for a long time, or if you anticipate intense sun exposure (eg, while at the beach or skiing).

How much sunscreen do I need? — You should apply sunscreen generously to all exposed skin 15 to 30 minutes before exposure. Exposed skin is any skin that is not protected from the sun.

You need approximately 1 ounce (2 tablespoons) of lotion to cover an adult's arms, legs, neck, and face. You may need more sunscreen to cover your chest and back. Applying less than this amount may reduce the sunscreen's SPF rating.

You should reapply sunscreen after sweating, rubbing the skin, drying off with a towel, or swimming. The traditional advice is to reapply sunscreen every two to three hours. However, some evidence suggests that reapplying sunscreen as soon as 20 minutes after going outside may offer greater protection, allowing you to completely cover areas that you might have missed when you first applied sunscreen. You should then re-apply every 2 to 3 hours.

Protect your lips with lip balm containing a SPF of 30 or higher and re-apply frequently. Some cosmetic products (eg, liquid foundation, lipstick) contain sun-protective ingredients, although to be truly effective, these products should be labeled as having an SPF of 15 or higher.

Does sunscreen expire? — Chemical sunscreens may become less effective over time, and leaving them in high temperatures (eg, car, beach) may speed the process. Manufacturers and others recommend throwing away sunscreen when it has passed the expiration date listed on the bottle. For sunscreen that does not have an expiration date, a typical recommendation is to throw it away after three years. Expired sunscreen may be less effective, potentially reducing the SPF rating and increasing your risk of sunburn.

Clothing — In addition to sunscreen, consider covering exposed skin with a wide-brimmed hat, long-sleeved shirt, and long pants. A hat made of tightly-woven material (eg, canvas) can provide shade for the face, ears, and back of the neck. Sunglasses that provide 100 percent UV ray protection can reduce your risk of cataracts (clouding in the eye's lens); wraparound glasses provide the most complete protection.

Clothing made from tightly-woven dark fabrics tends to provide greater protection than light-colored fabrics. Some manufacturers have sun-protective clothing with SPF. In addition, UV absorbing agents can be applied to clothing in the laundry.

Tips for children — Children are at higher risk than adults for becoming sunburned for several reasons. Children are usually unaware of the risks of sunburn and are less likely to use preventive measures (eg, sunscreen, shade).

The safety of sunscreen has not been tested in infants younger than six months, and sunscreens are not usually recommended for this age group. Instead, parents are encouraged to use hats, sunglasses, and shade to protect children from the sun. However, you may apply a minimal amount of sunscreen with an SPF of 15 or higher to small areas in young infants (eg, face, back of hands) when adequate clothing and shade are not available. Sensitive skin or "baby" formulas are recommended.

SUN TANNING

Tanning increases your skin's production of melanin, which provides some minimal protection to the skin against further damage from UV radiation. However, the small benefit of tanning (protection from sunburn) does not outweigh the risks (skin cancer, aged skin).

Outdoor tanning — If your skin tans after being in the sun, gradual sun exposure that allows tanning appears to decrease the risk of sunburn. However, tanning also increases the long-term consequences of sun exposure, such as skin cancer and wrinkling. Thus, gradual tanning in the sun is not the best method for preventing sunburn.

Tanning beds — Tanning beds use a mixture of ultraviolet rays, similar to the mixture emitted by the sun. The benefit of tanning beds in preventing sunburn is not clear and most experts do not recommend tanning beds to prevent sunburn. Tanning beds can cause sunburn and have been linked to an increased risk of melanoma, a potentially deadly form of skin cancer. Most experts do not recommend using tanning beds, especially for those under age 18 years.

Safety tips — If you choose to use a tanning bed, there are some important safety tips to remember.

• Use protective eyewear while the sun lamp is on.
• Limit the amount of time spent in the tanning bed, as recommended by the facility.

Sunless tanning — As people become more aware of the risks of skin cancer from sun exposure and tanning beds, sunless tanning products have become increasingly popular. A variety of safe and natural-appearing sunless tanning products are available, including lotions, gels, and sprays.

These products stain the skin, making it darker. The staining is temporary, usually lasting less than one week unless you reapply the product. While sunless tanning products are generally safe, the "tan" you get does not protect against sunburn.

Other tanning products — Tanning accelerators and tanning pills are advertised to darken the skin, either in combination with sun exposure or by coloring the skin directly. However, these products have not been tested it is not clear if they are safe; the sale of tanning pills has been banned in the United States.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed every four months on our web site (www.uptodate.com/patients).

Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information

Patient information: Sunburn

Professional level information

Primary prevention of melanoma
Risk factors for the development of melanoma
Sunburn
Vitiligo

The following organizations also provide reliable health information.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/sunexposure.html, available in Spanish)

• Center for Disease Control and Prevention

       (www.cdc.gov/cancer/skin/chooseyourcover/)

• The National Cancer Institute

       (www.nci.nih.gov/cancertopics/pdq/prevention/skin/Patient/page2)

• The Environmental Protection Agency

       (www.epa.gov/sunwise/)

• The Skin Cancer Foundation

       (www.skincancer.org/index.php)

• The National Council on Skin Cancer Prevention

       (www.skincancerprevention.org)

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