Are the Big Moles on My Child Dangerous? Leading Dermatologist Dr. Joshua Fox Discusses Moles in Children, Including Big Ones on Their Backs

Sep 18, 2011

Are you worried about all those big moles on your child’s back? Most people are born without “birth marks.” A recent study shows that every beach vacation gives rise to a 5 percent increase in the appearance of small moles on a child.

Dr. Joshua Fox says, “The development of new moles is of concern, because the higher the number, and the more irregular moles, the greater the risk for developing melanoma, the most dangerous of the skin cancers.”

What about big moles on my child’s back?

Dr. Fox is founder and director of New York and New Jersey-based Advanced Dermatology P.C. I asked him (for purposes of this article) specifically about large moles all over a child’s back: Does this reflect excessive sun exposure? My teen nephew has many big, funny-looking moles all over his back, and he is almost always shirtless on summer lake vacations and tropical vacations.

Dermatologists call moles “nevi” (rhymes with Levi, as in Levi jeans), and the singular form of nevi is “nevus.” Odd looking or atypical nevi are called dysplastic nevi, and they can resemble melanoma. Having dysplastic nevi is a risk factor for melanoma.

Dr. Fox says that most nevi are not worrisome, but as a parent you should monitor your child’s skin for any changes in nevi or new nevi. This will be challenging if your child has a lot of spots, like my nephew. If your child has a lot of moles on his back or elsewhere, it would be very smart to pursue serial digital dermoscopy as a way of tracking all the nevi.

Relationship between moles on child’s back and sun exposure

“Many dysplastic nevi seem to occur in areas in which the child received severe sunburn on one or more occasions,” says Dr. Fox. “It often matches the clothing distribution. In addition, there is a genetic relationship to melanoma. Only about 1 percent of infants are born with a mole. For those children who have many nevi, we encourage parents to check their child’s moles monthly to detect changes.”
If you notice a new “birth mark” on your child, keep visual track of it. “Normal looking new moles are not suspicious,” says Dr. Fox. About one-third of melanomas arise in a pre-existing nevus.

“By the time most people reach adulthood, they have between 10 and 40 moles,” says Dr. Fox. A lot of sun is another risk factor for melanoma, and maybe as a parent you’re not overly concerned about your child developing melanoma since this is extremely rare in kids.

However, older age is a risk factor for melanoma, and childhood sun exposure can lay the groundwork for melanoma risk decades later! In other words, parents should see the big picture: Their child’s risk of melanoma when their “kid” is 40 years old!

If you’re inspecting your child’s back moles (or elsewhere) for the first time and notice that some look funny, this doesn’t mean melanoma. Get familiar with the nevi so that you can detect a changing or evolving nevus. Follow your gut feeling and make an appointment with a dermatologist if your child has a suspicious looking skin lesion.

Concerning signs include irregular shape, jagged edges, red portions within the nevus or varying colors, larger than a pencil eraser, and of course . . . changing.

How often should I check the moles on my child’s back?

Every month, and inspect any area exposed to sun including the scalp and behind ears. Draw a mole map and take photos and compare every month. If this is overwhelming, pursue serial digital dermoscopy, which is ideal for kids and adults who have many moles on their back.