CHILDREN'S FUN IN THE SUN MAY MEAN SKIN PROBLEMS LATER.

Byline: Dr. Seth Orlow

Summer is almost here and it's important to know how to protect your child against the damaging effects of exposure to the sun.

Deterioration of the atmosphere's ozone layer - which screens out the sun's most damaging ultraviolet rays - has made everyone more vulnerable to ills from the sun.

But it is especially important that children get protection because 60 percent to 80 percent of lifetime sun damage occurs by the time youngsters are 18 years old. And the sun's effects on the skin are cumulative and irreversible.

Sun damage occurs as a result of exposure to two forms of ultraviolet radiation in sunlight. Ultraviolet A rays penetrate deep into the skin and can cause premature aging, sunburn and skin cancer. These rays reach the Earth's surface at a constant level all year-round.

Ultraviolet B, the second type of light, is more intense than UVA during the summer months. It is exposure to these rays that is associated with an increased risk of sunburn and skin cancer.

For youngsters, acute exposure can be dangerous. One blistering sunburn during childhood or teen years doubles a person's risks of developing skin cancer later in life.

Protection against the sun begins with your child's clothing. If your youngster is going to be out in the sun, select clothes that have a tight weave. These fabrics reduce the amount of light that can penetrate to the skin. As part of the outfit, add a wide-brimmed hat that shades the face and ears.

Another key to sun protection is a sunscreen lotion. Look for a waterproof sun block that has an SPF, or sun protection factor, of at least 15. The sunscreen should also be labeled as broad-spectrum, meaning that it blocks both UVA and UVB.

Apply the sun block indoors at least a half-hour before your child ventures outdoors. This allows adequate time for the sunscreen to penetrate the skin. It can also prevent sunburn at strap lines or frequently missed areas where clothing may shift and expose unprotected skin.

Be sure to use sun block on all exposed areas, such as the face, hands, feet and back of the knees. For protection of sensitive areas, such as the ears, nape of the neck and tip of the nose, use a sunscreen with a higher SPF.

And don't forget to reapply the sunscreen every few hours, if children are playing in water.

Even with these precautions, it's important to try to plan outdoor activities for early morning or late afternoon. This will keep children out of the sun between 10 a.m. and 3 p.m., when rays are at their strongest.

A special note on infants: Babies have thinner and more sensitive skin that is more prone to sun damage than older children and adults. Infants younger than 6 months should be kept out of direct sunlight and away from surfaces that reflect the sun's rays such as sand and poolside concrete. When outdoors, stick to the shade of an umbrella, tree or stroller canopy.

Contact a pediatrician if a baby younger than 1 contracts a severe sunburn. This can cause fever and dehydration and can become a medical emergency.

MEMO: Dr. Seth Orlow is director of pediatric dermatology and associate professor of dermatology and pediatrics at New York University School of Medicine.