The other day, somebody bent down to get something off the floor for me, and I noticed she had one of those birthmarks that a lot of people have -- a red or sometimes pink, longish, irregular patch at the nape of the neck that looks kind of like a rash. Usually you can't see it because it's hidden by hair, but with some people, it's pretty apparent.
I heard, once upon a time from some crazy people in a hair salon, that this was not a birthmark but actually a sign that many toxins had built up under your scalp. So I finally decided to find out if this is true.
- The red patches are known as "stork bites," suggesting that this is where the mythical stork held you in its beak as it carried you to be born. They are also called "salmon patches."
- They are birthmarks, a particular type unto themselves. They are caused by poorly formed blood or lymph vessels. The patches are where the dilated capillaries are visible under the skin.
- Stork bites are extremely common. Different sources give different rates of occurrence, but they appear in anywhere from 1 in 5 to 1 in 2 newborns.
- They become more visible when the baby cries or when its temperature changes. If you apply pressure to it, the coloring fades, but when you remove pressure, the coloring comes back.
- Babies can also have these patches on their faces (quaintly, sometimes called "angel kisses"). The patches in these places typically fade as the baby gets older. As for stork bites, however, they do not go away in 50% of the people who have them.
- I was wondering if maybe the trauma of birth made these marks appear, but apparently, nobody knows what causes them.
As a general observation, I've found this to be true of a lot of medical knowledge. They can tell you a lot about where and when something weird occurs in the human body, and sometimes even how it all works. But most of the time, they have no idea why it happens. Somebody really ought to get on the why part.
University of Maryland Medical Center, Medical Encyclopedia, Stork Bites entry and Birthmarks - red entry
Dr. Joseph F. Smith Medical library encyclopedia, Birthmarks entry
Healthwise Knowledge Base & Reuters Headlines Topic: Birthmarks