Moles are common skin growths that occur when skin cells called melanocytes cluster together inside a covering of tissue. They frequently appear in childhood or adolescence, and are sometimes present at birth. Although typically harmless, in some cases, moles can develop into skin cancer or can harbor cancer cells.
In most cases, children develop moles at some point after birth, according to the American Academy of Dermatology. Typically, these common, benign moles arise in areas of your child’s skin that receive sun exposure. Initially, they appear as round, flat spots with a single, uniform color. As your child grows, common moles grow as well, keeping symmetrical borders and a generally round structure. In some cases, they may lighten prior to puberty, then darken again when puberty begins. Despite these changes, they typically have a single, even color at any given time. By adulthood, your child will likely have between 12 and 20 moles of this variety.
In some cases, your child may develop moles that do not resemble common moles, the American Academy of Dermatology notes. Although usually harmless, these atypical moles have some chance of turning into skin cancer, according to Children’s Hospital Boston. Signs that your child’s mole is atypical include the presence of ragged or irregular borders; a lack of symmetry between the mole's two halves; a diameter larger than a pencil eraser; and variations in color throughout the mole. If your child has a mole with these types of irregularities, you will need to watch it carefully and report any changes in its appearance to your child’s doctor.
Roughly 1 percent of children are born with a mole, the American Academy of Dermatology reports. In many cases, these congenital moles appear similar to common moles, but they may also look like bluish-gray bruises. If your child’s congenital mole measures less than eight inches in diameter, it typically indicates no increased risks for the development of skin cancer. However, if your child’s congenital mole measures more than eight inches, he may experience an increased skin cancer risk of between roughly 5 and 10 percent. In some cases, this risk increase may be even greater.
Spitz Nevus Moles
Your child may also develop a dome-shaped, raised mole called a Spitz nevus, which highly resembles active skin cancer, the American Academy of Dermatology explains. Moles in this category are frequently pink, but other potential shades include brown, red and black. In some cases, these types of moles may also bleed or produce an oozing fluid. Be aware that Spitz nevus moles look so much like cancer that even a specialist cannot differentiate the two during a visual examination.
Children’s Hospital Boston and the American Cancer Society list tips for examining your child’s moles that include familiarizing yourself with your child’s skin characteristics; systematically scanning your child’s body from front to back and right to left with his arms raised; and closely checking easily overlooked locations such as the spaces between his toes and his scalp, back and buttocks.