Moles on a young child’s skin are generally nothing to worry about. It is normal for new moles to appear during childhood and adolescence. Moles will grow as the child grows. Some moles will darken, and others will lighten. These changes are expected in children and seldom a sign of melanoma — a type of skin cancer that can begin in a mole.
While melanoma is rare in young children, it is helpful for parents to know that there are different types of moles. Most moles are harmless, but there are a few types that should be examined by a dermatologist just to be sure. The following guide explains why.
A Parent’s Guide to Moles
Common mole. Also referred to as a beauty mark or acquired nevus (mole), a common mole is harmless. Most moles that develop on a child’s skin are common moles.
Common moles appear during childhood and adolescence. These moles arise on skin that gets sun exposure and begin as a flat, round spot that is one color throughout. As the child grows, this benign (non-cancerous) mole grows symmetrically. This is, both sides look the same. A benign mole may rise above the surface of the skin and can lighten over time. During puberty, however, benign moles generally darken. Regardless of whether a mole lightens or darkens, the color stays uniform throughout. By the time a child become an adult, there are typically 12 to 20 common moles on the skin. Few benign moles develop after 30 years of age.
What dermatologists recommend: Common moles develop in children and teenagers and are generally nothing to worry about. If a mole looks different from the others, itches, or bleeds, the mole should be examined by a dermatologist.
Congenital mole. When a child is born with a mole, dermatologists refer to the mole as a congenital nevus. Congenital moles are considered a type of birthmark. About 1% of newborns have a congenital mole.
These moles take various forms. Some look like common moles. Others are bluish-gray spots that can resemble a bruise. The latter are called Mongolian spots and are more common in Asian, Native American, brown, and black skin. Mongolian spots often fade during childhood.
Most congenital moles are harmless. A large or giant congenital nevus, however, poses an increased risk of melanoma. What defines a congenital mole as a giant is its diameter. When the diameter is greater than 20 centimeters (about 8 inches), it is considered a giant. Some estimates indicate that having a large or giant congenital nevus increases the risk of developing melanoma by 4.5% to 10%. Other studies conclude that this risk may be even higher.
What dermatologists recommend: When a child has a giant congenital nevus, the mole should be examined by a dermatologist. The risk of developing melanoma is greatest during the first 10 years of life and especially high during the first 5 years.
Dysplastic mole. A mole is classified as dysplastic when it does not look like a common mole. Common moles are symmetrical, have one consistent color throughout, and tend to be smaller in diameter than a pencil.
Dysplastic moles, also known as atypical moles, do not have these features. Instead, dysplastic moles have one or more of these traits: Asymmetrical (if folded in half, the sides would not match), an irregular border, more than 1 color in the mole, and a diameter that exceeds 6 millimeters (about the diameter of a pencil eraser).
What dermatologists recommend: If your child has dysplastic moles, the child should have routine skin exams after puberty.
Spitz nevus. This mole so closely resembles melanoma that it is not possible for a dermatologist to look at a Spitz nevus on the skin and tell whether or not it is a melanoma. A Spitz nevus often is a pink, raised, dome-shaped lesion. It also can contain variable colors such as red, black, and brown. The mole may bleed. It can have an opening that oozes.
Most Spitz nevi appear on the skin during the first 20 years of life. Spitz nevi also develop in adults.
What dermatologists recommend: When a lesion resembles a Spitz nevus, it should be examined by a dermatologist — regardless of the person’s age.
Other Risk Factors Parents Should Know About
If numerous moles develop on your child’s skin or a mole is larger than 6 millimeters, this increases the risk of developing melanoma. Even if the moles look harmless, there is still an increased risk. Several studies have found a relationship between the number of moles and an increased risk of developing melanoma. A study that looked at melanoma in Australian patients aged 15 to 19 years old found that more than 50% of these patients had in excess of 100 moles. These patients also tended to have a greater density of moles on their skin and moles larger than 5 millimeters.
Other risk factors that can significantly increase the risk of developing melanoma include a family history of melanoma, weak immune system, and tendency to get sunburn. Some medical conditions such as xeroderma pigmentosum (a rare genetic disease) and familial atypical mole and melanoma syndrome (FAMM) also increase the risk. FAMM occurs when a person has one or more close blood relatives with melanoma, lots of moles (50 or more), some dysplastic moles, and moles that display certain characteristics when viewed under a microscope