Birthmarks, just like their name implies, are skin issues that are present since birth. The cause of many birthmark varieties is unknown but some have genetic roots since they can affect the same family. Depending on their location and severity, the doctor decides if a birthmark must be treated or can be safely ignored. Moles and vascular birthmarks can be removed through laser surgery but pigmented ones are rarely treated.

Some birthmarks fade away without any treatment and most of them are harmless. The majority of them do not change, while a few can actually become a concern with age. Some of them are dangerous because they increase the chance to develop skin cancer but most are only a cosmetic problem. You should ask for medical advice if a birthmark becomes infected or starts to itch or bleed.

Birthmarks are found in two common types and several less common ones. The most common variety is the vascular birthmarks, which are actually irregular blood vessels located on the skin or under it. Due to their nature, they tend to be red or associated colors like purple or pink. The second common type are usually brown and are caused by grouped pigment cells, being named pigmented birthmarks.

Both of these types can appear anywhere, not only on the skin but also inside the body. However, vascular birthmarks are typically found on the face, head or neck. Since they are caused by blood vessels close to the skin surface, vascular birthmarks are red, pink or purple. Sometimes, the blood clusters appear to be blue, if located deep inside the body. Pigmented birthmarks usually have a dark color, either brown or tan.

Vascular birthmarks

Vascular birthmarks are some of the most common and they can be further divided into several types.

One type of vascular stains are known as stork marks, stork kisses, stork bites or salmon patches. These are caused by the dilation of capillary blood vessels located very close to skin surface. They are either pink or purple, with a flat profile. Of all possible birthmarks, this is by far the most common type and around 70% of all babies have at least one salmon patch. Changes of temperature make them more visible, as well as moments when the baby is agitated or cries. Most of these signs disappear without any treatment, such as the so-called angel kisses on the eyelids or forehead. Some can last the entire life, for example the stork bites on the back of the neck.

Strawberry marks, scientifically named infantile haemangiomas, have a raised profile and can show up on any area of the body. Just as the name suggests, they are red and similar to a strawberry. However, they can also be located deep under the skin, when they have a different color, either purple or blue. Around 5% of all babies have strawberry marks at birth, girls seem to have a higher risk. In the first six months of life they can quickly expand in size but this should not be a real cause of concern, since they start to decrease afterwards and by the age of seven they are usually gone. However, infantile haemangiomas might require treatment if they grow too large or if they prevent vision or feeding.

Port wine stains, or capillary malformations, are very rare and only a very small number of babies have them. They are flat, with either a red or a purple color. Some of them are not larger than a few millimeters, but there are cases when they can have a diameter of several cm.

Capillary malformations can appear anywhere on the body but the usual locations are the face, back and chest. They tend to only affect one half of the body. Hormonal changes have a direct impact on their aspect, so their visibility increases in times of menopause, puberty or pregnancy. They persist into adulthood and their color can become darker.

Pigmented birthmarks

The second common type of birthmarks are the pigmented ones, which can also be classed into several types.

Some of the most usual are popularly known as café-au-lait spots, due to their color similar to coffee. They are extremely common and most babies will have a few of them. However, if a child develops a larger number before the age of five, you should be worried and ask for medical help. It is sometimes an effect of a genetic disease named neurofibromatosis, which forms tumours on the neural links.

Mongolian spots are a type of blue or grey birth lesions that resemble bruises. They can be found anywhere on the body but are the most common on the buttocks and lower back area. For some reason, people with dark skin have a higher risk to develop them. Besides the fact that Mongolian spots are constantly mistaken for bruises, they don't require any treatment and are not dangerous. In most cases they are gone by the age of four but some can last for a few years more.

Congenital moles, with the scientific name congenital melanocytic naevi, are the moles that are present since birth. They look similar to other mole types but tend to be larger, with the same brown or black color.

Many babies have these kind of moles, which are the result of an unusual number of pigmented cells in the skin. In most cases, they decrease in size and completely disappear in time. The opposite can happen as well, and some can become darker and more visible during puberty. Some naevi can become covered with hairs.

These congenital growths have a medium or large size, starting from a diameter of about 1.5 cm to over 20 cm. All moles have a low chance to transform into skin cancer but the large ones have a higher risk.

What causes birthmarks?

The exact cause of birthmarks remains unknown, some of them seem to be inherited but the majority are not. Vascular types are the result of faulty blood vessels at skin level, while groups of pigment cells lead to pigmented birthmarks.

Port wine stains are special and their exact mechanism is not well understood. It seems that the expansion and contraction of capillary blood vessels doesn't function well, probably due to a problem with the nerves that control this function. As a result, a constant flow of blood reaches the area, giving it a permanent red or purple color. These lesions might have a more complex cause, since they can sometimes be linked with other issues like the Sturge-Weber syndrome and Klippel-Trenaunay syndrome. Other complications are possible as well.

Treatment options

In most situations, birthmarks are not a cause of concern and require no treatment. Many of them disappear in time, or at least become less noticeable. Port wine stains and some other types persist into adulthood and can only be removed by treatment.

Birthmarks are most often treated for cosmetic reasons. However, they can also cause medical problems or complications. For example, some haemangioma can grow very large, blocking respiration or vision, sometimes turning into ulcers.

The treatment depends on the birthmark's type. They can be removed through conventional surgery or more modern laser techniques but these procedures will usually cause a scar. Steroids and beta-blockers, delivered in topical or oral form, can also be effective in some cases.

For a long time, there was no treatment against port-wine stains. However, the discovery of pulsed-dye laser was a major breakthrough and these can now be eliminated, especially those located on the face.