Article from Yahoo Parenting, by, Rachel Grumman Bener, published April 10, 2015
There’s nothing cuter than a kid with freckles but have you ever wondered why babies rarely have them?
Freckles are a phenomenon that occurs when genetically predisposed people (often those with fair skin, red hair, and light eyes) are exposed to UV light over time, according to Joyce Teng, MD, director of pediatric dermatology for Lucile Packard Children’s Hospital Stanford. The average age that children develop freckles is between two and four years old. “As kids get older, they start walking [on their own], doing more activities outdoors, and naturally have more sunlight exposure,” Teng tells Yahoo Parenting. This can trigger a smattering of freckles, particularly on children’s faces. While freckles are cute, they’re sadly a warning sign of sun damage.
That doesn’t mean that every freckle is on the verge of becoming skin cancer. “But freckles are a good indicator of how sensitive your skin is to sun exposure and whether you’re at a slightly higher risk,” says Teng.
Although it’s not completely understood why you almost never see infants with freckles, a look at how freckles are created may offer some insight: Melanocytes are cells that produce pigment in the skin, including freckles. “As kids get older, with increased UV exposure, the body starts to make more melanocytes, which work harder to produce pigment to protect [the skin, resulting in freckles in some],” explains Teng. “It’s possible that these cells are not mature enough yet [to produce freckles] in infants.”
Teng also notes that melanocytes only occur at the basal layer of skin, which is the deepest layer of the epidermis (the outer layer of skin). So sunlight doesn’t instantly trigger the formation of freckles. “The light gradually filters through the skin and activates melanocytes to make pigment darker than its neighboring cells—it takes time,” she says.
Bottom line: Sun damage in childhood increases the risk of skin cancer later on in life, so protect your baby. “The most important thing is to try to avoid direct sunlight at [midday] and use physical blocks, like shade and a hat,” she says. Although the general recommendation is to not use sunscreen on infants younger than six months old, Teng says it’s safe to use zinc oxide. “You see zinc oxide in diaper rash creams, and we don’t tell parents not to use diaper cream for the first six months,” she says. “Have babies wear a hat and a shirt and just use zinc oxide on the exposed areas. That amount won’t harm your baby.”
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