Studies have shown that 80 percent of lifetime sun exposure occurs before 18 years of age. Over-exposure to the sun greatly increases the risk of developing non-melanoma skin cancer - the most common form of cancer in the United States - and several studies have associated severe childhood or adolescent sunburns with the development of malignant melanoma, a potentially lethal form of skin cancer, later in life.
   That's why pediatric experts at Children's make a point to educate parents about the effects of the sun's harmful rays on children. Protecting children from sun damage at an early age develops good habits and it may reduce the incidence of non-melanoma skin cancer later, says Dr. Patricia Hicks, a pediatrician on the medical staff at Children's and associate professor of Pediatrics at UT Southwestern.
   "Forming a sun protection habit early in life is similar to seatbelt use," she said. "It is protective during childhood, but it also increases the likelihood that children will continue to practice those good habits later in life."

To achieve effective sun protection, Dr. Hicks recommends families:

• Use sunscreen with an SPF of at least 15 to 30.
• Apply sunscreen 30 minutes before going outdoors.
• Reapply sunscreen every one to two hours when outdoors, especially after swimming, perspiring or towel-drying.
• Avoid mid-day (10 a.m. to 4 p.m.) sun, whenever possible.
• Seek shade.
• Wear wide brimmed hats, sunglasses that block 99%-100% of ultraviolet rays, and shirts made of tight weave material.
• Keep infants out of direct sunlight.
• Use these sun protective measures even on cloudy days and in the non-summer (fall, winter) months.

Sunscreen vs. sunblock
Chemical sunscreens act as a filter to absorb ultraviolet light in a specific range. Chemical sunscreens include benzophenones (oxybenzone, sulisobenzone), PABA (aminobenzoic acid, padimate O, glyceryl PABA), methoxycinnamate and avobenzone (Parsol 1789).
   Most chemical sunscreens absorb UVB radiation, however the benzophenones absorb some UVA radiation and avobenzone gives significant UVA protection. Commercial sunscreens often combine more than one chemical sunscreen to provide what is called broad-spectrum, or UVA and UVB protection.
   According to the American Academy of Dermatology, sunscreen has long blocked UVB effectively and new ingredients like octylcrylene, the benzophenones and avobenzone work to screen a variety of UVA rays.

Physical sunblocks (zinc oxide and titanium dioxide) act as a barrier to deflect the ultraviolet light. They protect consistently and effectively against both UVA and UVB radiation.
   Sunblocks are opaque, but more transparent micronized forms are now available. Sunblocks also tend to be less irritating when applied to sensitive skin, such as the face, and do not tend to cause allergic reactions.
   The AAD reports that new preparations for sunblocks, such as micronized titanium dioxide, offer substantial UVA and UVB protection. Newer sunblocks are less conspicuous on the skin and are more cosmetically acceptable than the original thick, white sunblocks.
    
Proper techniques
Dr. Hicks said some common mistakes include not applying an adequate amount of sunscreen and neglecting the following areas:

• Ears
• Neck
• Tops of the feet
• Exposed scalp

While there is no quick cure for minor sunburn, the AAD suggests moist compresses, tub baths and soothing lotions to provide some relief.

Protecting infants
If shade is unavailable to protect an infant, Dr. Hicks recommends using an umbrella or placing a blanket or towel over the carrier to provide protection from the sun, although she warns that refracted rays can still reach the infant under such shade.
   Other steps to take include dressing infants in protective clothing and hats and using protective shields on car windows.
   "For infants, most physicians prefer these sun protection methods over sunscreens, although there is no evidence that sunscreens are harmful to infants," Dr. Hicks said. "In situations where sunscreen is desired, physical sunblocks, namely zinc oxide and titanium dioxide, would be preferred over chemical sunscreens since they are less irritating and have little to no cutaneous absorption."
   Dr. Hicks added that zinc oxide has a long record of safety in infants, since it is a commonly used therapy for diaper rashes.
  
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