What are Birthmarks?

Birthmarks are discolorations, lack of pigment or discoloration due to abnormal development of blood vessels. They appear on the skin shortly after birth. The cause of most birthmarks is unknown. Most birthmarks are harmless, but some are large or prominently placed, causing treatment to be desirable. In some cases, birthmarks are large enough and extensive enough to interfere with normal function.

Types of Birthmarks

There are two major types of birthmarks: vascular birthmarks and pigmented birthmarks. Vascular birthmarks include port wine stains, "stork bites," and "strawberry" hemangiomas. Pigmented birthmarks include "Mongolian" spots, cafe-au-lait marks and moles. Vascular birthmarks tend to be red in color, while pigmented birthmarks are blue, brown or black and sometimes look like bruises.

When a Birthmark Might Be a Problem

Some birthmarks can indicate serious underlying conditions. For example, the presence of multiple cafe-au-lait marks can indicate the presence of neurofibromatosis, a genetic disorder that leads to tumors throughout the skin and nervous system. Very large hemangiomas can interfere with breathing, sight or the ability to eat. When these vascular birthmarks prove to be a problem, surgical treatment might be necessary.

In general, birthmarks are harmless. Many disappear in the first few years of life, especially vascular birthmarks. Others simply add to a child's individuality without causing problems or issues of any kind.