Contrary to their name, birthmarks aren't always present at birth. Some, such as a hemangioma, develop weeks later. And though most are permanent, a few types of birthmarks fade as a child grows.
Most birthmarks are harmless, but some may require treatment for cosmetic reasons or because of rapid growth. Still others may be a sign of an underlying disease. Take this visual tour of cafe au lait spot, port-wine stain and other common birthmarks, and find out when your child might need to see a doctor.