By Anne Harding

NEW YORK (Reuters Health) - Very light-skinned children who tan in the sun develop significantly more moles than their peers who stay pale in the sun, new research shows.

The number of moles a person has is among the strongest risk factors for developing melanoma, the most deadly form of skin cancer, so the findings suggest that parents of these children should take extra care to protect them from the sun's rays, Dr. Lori A. Crane of the University of Colorado in Denver and her colleagues conclude in a report in the Archives of Dermatology.

While sunburns are known to increase melanoma risk, Crane and her team note in the report, the effect of tanning on skin cancer risk isn't clear; in fact, some studies suggest it's protective.

To investigate, they looked at 131 very-light-skinned children and 444 darker-skinned white kids born in Colorado in 1998. All underwent full-body mole counts at age 6, 7 and 8 years.

The researchers gauged their skin color using a device called a colorimeter. To determine whether or not the children tanned, they used the device to compare the color of their skin at the inside of their upper arm to the color of the skin on the outside of their lower arm.

At age 6, the average number of moles for the minimally tanned light-skinned children was 14.8, compared to 21.2 for the more darkly tanned children. At age 7, the paler kids had 18.8 moles, on average, while the tanned kids had 27.9 moles. By age 8, the untanned children had 22.3 moles, compared to 31.9 for the tanned kids.

But among the darker-skinned children, whether or not they were tanned made no difference in the number of moles they had on their bodies.

The current study didn't determine whether the untanned children were simply unable to tan, or had been protected from the sun, Crane told Reuters Health. No matter what, she added, the findings suggest "there should be more careful protection of those children, which is probably not very surprising."

And parents shouldn't rely on sunscreen alone for shielding kids from the sun, the researcher added; while it can protect against sunburn, it doesn't do a good job of preventing tanning.

Also, she added, parents may let their children stay out in the sun longer when they wear sunscreen, which could be harmful. Crane suggests protecting kids with lightweight, loose clothing, including hats, and avoiding the strong mid-day sun.

SOURCE: Archives of Dermatology, September 2009.

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