Birthmarks are raised or colored marks on the skin that are either present at birth or develop shortly thereafter. Some birthmarks only affect the surface of the skin, while others can be raised above the surface or extend into the tissue underneath. Birthmarks often fade as a child ages, although some are permanent. Most birthmarks do not require treatment.
Many scientists believe that birthmarks are caused by the deformed pigment cells or blood vessels. For instance, so-called vascular birthmarks are caused by enlarged small blood vessels just beneath the skin's surface, and usually grow while a fetus is in the womb. They are usually red or purple colored. The most common types are mild red marks, known as "angel's kisses" when located on the forehead or eyelids, and as "stork bites" when they appear on the back of the neck.
Strawberry hemangiomas are slightly raised red marks made of small closely packed blood vessels, usually appearing on the face, scalp, back and chest. They usually disappear by age 10. If a child develops a bluish-colored mark shortly after birth, this is called a cavernous hemangiomas. About 10% of all babies are born with hemangiomas. Port wine stains show up as red or purple blotches on the skin, and are usually permanent. Former Soviet leader Mikhail Gorbachev has a very prominent port wine stain on his forehead. It's caused by a web of widened capillaries underneath the skin.
Other forms of birthmarks include light tan spots the color of café au lait (coffee with milk), and nevi, or moles. Moles are small clusters of pigmented skin cells, sometimes raised, and almost everyone has them. As we age, moles have an increased risk of becoming cancerous, and should be checked regularly.
Intense pulsed laser light is often used for treatment of vascular skin lesions, although this can sometimes cause scarring and harm neighboring skin patches.
The American Association of Physicists in Medicine contributed to the scientific content of the TV portion of this report.