Birthmarks are blemishes on the skin that are noticeable at birth, or shortly afterwards. A significant proportion of newborns have a birthmark.
Vascular birthmarks – a red, pink, or purple blemish – are caused by abnormal blood vessels under the skin.
Some people are born with pigmented birthmarks; these are usually brown and are caused by the clustering of pigment cells.
In this article we will look at the types of birthmarks and their causes, complications and treatments.
What is a birthmark?
Despite their prevalence, birthmarks are still a fairly mysterious phenomenon.
Nobody really knows what the causes of birthmarks are. Experts say that vascular birthmarks are not hereditary.
Birthmarks are less common in Asian people, compared to individuals from other parts of the world.
According to folklore in Spain, Italy and some Arabic countries, birthmarks are caused by the unsatisfied wishes of the mother during pregnancy.
For example, if a craving for strawberries was not satisfied, her child would be born with a strawberry mark on his/her skin.
Birthmarks used to be called “voglie” in Italian, “antojos” in Spanish, and “wiham” in Arabic – meaning “wishes” or “whims.”
Usually oval in shape, with a light brown or milky coffee color (hence the name). They are either present at birth or occur soon afterwards. As the individual gets older they do not fade. Some people may have one or two, but more are possible.
People with more than four may have neurofibromatosis (a genetically-inherited disorder in which the nerve tissue grows neurofibromas (tumors) that may be harmless or may cause serious damage by pressing on the nerves and other tissues).
Congenital melanocytic nevus
Image credit: M. Sand, et al., 4 June 2010
Affects approximately 1% of American infants. It can occur in any part of the body; in 15% of cases the marks are on the head and neck. In fair-skinned individuals it usually has a light brown color, while in darker-skinned people at may be almost black.
It can be have an irregular shape, may be flat, or raised and lumpy. They are relatively large brown or black moles. As the baby grows the marks become proportionally smaller. Sometimes they may darken or become hairy during puberty. Cancer risk is low, and is linked to size (the bigger the size, the higher the risk).
Image credit: Gzzz, 2 May 2014
Blue-gray marks commonly seen in darker skinned people.
The mark may look like a bruise and appear over the lower back or buttocks.
By the time the child is about 4 years old they have faded away. They are harmless.
Usually a red and raised mark, such as a strawberry mark. Most of them start off as small and flat. It is impossible to know whether they might grow later on. Usually, they grow quickly during the baby’s first four or five months of life, then the growth slows down and many eventually fade. In some cases the skin may become stretched or deformed, especially if it is a large mark.
Also called salmon patch and stork mark/bite, they are caused by dilations (expansion) in the capillaries (tiny blood vessels). They are patches of slightly reddened skin. A salmon patch on the face is often called an angel kiss, and a stork bite/mark when it appears on the back of the neck. Angel kisses will usually fade within a couple of years; sometimes they may become visible again if the child cries. Stork marks tend to stay, but are usually covered by hair.
Port wine stain
Red or purple marks that commonly affect the face, but may occur anywhere, caused by abnormal bleeding of blood vessels in the affected area. In the UK, the NHS (National Health Service) informs that approximately 3 in every 1,000 newborns have port-wine stains. They may vary in size form a few millimeters to several centimeters.
If left untreated they may eventually get darker. About 10% of babies born with port wine stains may have one in the eyelid area and might need specialist treatment and/or monitoring. In a very small number of cases, there may also be brain abnormalities (Sturge-Weber syndrome).
Image credit: Dr. Gary White, http://www.regionalderm.com/index.html
Known to be hereditary; a silver streak of hair, usually found at the right or left side where the forehead and hairline meet.
Commonly, other family members also have a silvermark.
Causes of birthmarks
Experts do not fully understand why some babies have birthmarks while others do not. Most experts agree that vascular birthmarks are not inherited.