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."
Types of birthmarks
Birthmarks are broken down into a number of subtypes. These are the seven most commonly seen versions:
Café au lait spot
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.
An over-accumulation of cells that make up the lining of the baby's blood vessels are believed to cause the development of strawberry marks.
In some cases, experts believe that a tiny piece of placenta may have got lodged inside the developing embryo very early during pregnancy.
If the nerves that control the dilation (widening) or constriction (narrowing) of capillaries are damaged, there is a risk of port wine stains, especially if the capillaries are permanently widened in one area.
Salmon patches are caused by an accumulation of capillaries under the skin.
Some experts believe that some proteins produced by the placenta during pregnancy may be linked to a higher risk of developing some types of birthmarks.
Complications of birthmarks
Birthmarks are rarely a cause for medical concern.
The vast majority of birthmarks pose no long-term health problems to the child; many of them eventually fade away.
Some birthmarks, such as strawberry marks, may turn into an open sore and become infected.
Some types of melanocytic nevi may develop into malignant cancers.
If the port wine stain is around the eye, there is a higher risk of developing glaucoma.
A strawberry mark that develops in the eyelid needs to be treated fairly promptly, otherwise there is a risk of developmental problems with the child's vision. Likewise, a strawberry mark that interferes with breathing or feeding may be life-threatening and will need prompt treatment.
A large port wine stain which extends onto the forehead or scalp is linked to a higher risk of having Sturge-Weber syndrome (a neurological disorder indicated at birth by seizures).
Treatment for birthmarks
A significant number of birthmarks fade away without any need for treatment. However, if the birthmark causes health problems, or if the patient feels strongly about getting rid of it, the doctor may recommend treatment.
Treatment can sometimes be painful and does not always work. Unless the birthmark is causing problems with sight, feeding, hearing, or breathing, parents need to weigh the potential problems with the expected benefits for the child. It is important to understand that not all birthmarks can be treated.
In many cases the doctor may be able to make a fairly accurate prediction of how the child's birthmark will progress.
- Corticosteroids: can be injected directly into the birthmark (hemangioma) or taken orally, to either stop it from growing or to shrink it
- Interferon alfa-12: if the costocosteroid does not work, this medication may be used instead to shrink or stop the birthmark from growing
- Laser therapy: commonly used for port wine stains and other birthmarks that are close to the skin's surface
- Surgery: if other therapies have not worked and the birthmark is causing a medical problem, the doctor may recommend surgery.
Treatment options depend on several factors, including the location and severity of the birthmark.