Question

My daughter's birthmark has hair growing out of it. Should I be concerned? Please help. It's a smooth brown one-inch birthmark.

Answer

What you describe sounds like a congenital nevus, meaning a mole present at birth. These are very common birthmarks, occurring in 1 out of every 100 babies. It's very common for hair to grow out of them, and this finding is not anything to worry about. It is important, though, to have the lesion followed by a health care provider, and for you to examine it periodically. Watch for these concerning features: rapid growth, asymmetry of the lesion, border irregularity, and color differences (especially if red, blue, or black areas are present). Although congenital moles may have a very slightly increased risk of melanoma, most of them can be followed by the pediatrician. If there are any concerning features or changes, then the definitive treatment is surgical excision.