Birthmarks

Shortly after meeting their new baby, many parents will take a quick look for birthmarks. They may find a mole, a red splotch, or a patch of skin that's a different color from the rest of the body. Birthmarks come in several different varieties, most of them harmless and easy to ignore. Some marks fade away over the years, and others, if desired, can often be removed or concealed.

There are two basic types of birthmarks. Red or vascular marks occur when blood vessels grow either larger or more abundantly than usual. Pigment marks occur when the skin makes too many of the cells that give it color. Although some types of birthmarks can be inherited, they are usually impossible to predict. There's definitely no one to blame; there's nothing a pregnant woman can do to either cause or prevent birthmarks.

Here's a look at common varieties of birthmarks:

Vascular marks

• Port wine stains are red or purple patches that usually show up on the face, neck, arms, or legs. (The red mark on Mikhail Gorbachev's forehead is the most famous example.) Caused by dilated capillaries near the skins surface, they can vary greatly in size. They won't change shape over time, but they can grow darker and more noticeable. They are only rarely painful, but they often make children feel uneasy about their appearance, especially if the mark is on the face. For this reason, many parents choose to have their child treated. Treatment with a "pulsed-dye" laser can lighten the stain and help it fade into the background. This treatment is often done in infancy, but it may need to be repeated in later years if the mark starts to darken again.
• Hemangiomas or "strawberry marks" are bright red bulges that most often show up on the head and neck. If the hemangioma is deep in the skin, it may be bluish. These marks may not appear until a baby is days or weeks old. They often grow rapidly for the first several months but then start to shrink. Because they generally disappear during the grade school years, they don't need any treatment unless they're growing in a place that makes it hard for a child to eat, breathe, or see.
• Macular stains, sometimes called stork bites or angel kisses, are faint red marks that most often appear on the face, eyelids, or back of the head. They usually disappear by toddlerhood.

Pigmented marks

• Mongolian spots are flat, bluish grey patches that are very common in babies with darker skin, including Asians, African-Americans, and Hispanics. More properly called a "slate grey nevus," this bruise-like mark most often appears on the lower back but can also show up on the buttocks, arms, or legs.
• Café-au-lait spots, as the name suggests, are light-brown spots that look a little like drops of coffee mixed with milk. These marks are very common and can show up anywhere on the body. They're usually easy to ignore, although a doctor will want to take a closer look if a child has several large spots, a potential sign of a genetic disorder called neurofibromatosis, a disease that causes tumors to grow on nerve cells.
• Moles, dark spots on the skin, are a common sight on all types of skin, including newborn skin. Some infants have large moles that reach several inches across. This type of mark, called a congenital nevus, usually appears on the trunk or the scalp. Babies born with these birthmarks are more likely to develop skin cancer later in life, especially if the moles are large. In such cases, the child's doctor can help parents learn to check for early-warning signs of cancer.

References

Cleveland Clinic. Birthmarks. http://my.clevelandclinic.org/disorders/birthmark/hic_birthmarks.aspx

Mayo Clinic. Birthmarks slide show. http://www.mayoclinic.com/health/birthmarks/SN00033

Nemours Foundation. Birthmarks. http://kidshealth.org/PageManager.jsp?dn=KidsHealth&lic=1&ps=107&cat_id=189&article_set=35902