Birthmarks

About birthmarks

Any mark that is present on the skin at birth, or that develops soon afterwards, is called a birthmark. They are common and many children have a mark of some sort. Most are harmless and some go away as the child grows. Occasionally, a birthmark may be a sign of other problems or diseases. Check with your doctor if you are not sure, especially if the mark changes unexpectedly.

Causes of birthmarks

In most cases, the cause of a birthmark is unknown. They are not caused by mothers doing something wrong during pregnancy. They happen by chance.

The occurrence of birthmarks may be inherited. Some marks may be similar to marks on other family members, but most are not. Red birthmarks are caused by an overgrowth of blood vessels. Blue or brown birthmarks are caused by pigment cells (melanocytes).

Types of birthmarks

There are various different types of birthmarks including:

• naevus flammeus, also known as a stork bite or stork mark
• Mongolian spots
• haemangioma of infancy, also known as a strawberry mark or strawberry naevus
• café au lait spots
• congenital melanocytic naevus.

Naevus flammeus or ‘stork bite’ mark

Other names for ‘stork bite’ mark include salmon patch or macular stain. The typical characteristics include:

• They are pink, flat and irregular-shaped marks.
• The skin is not thickened and you cannot feel any difference when you touch the mark.
• They are usually on the nape of the neck, eyelids, forehead and sometimes the sides of the nose and on the top lip.
• Nearly half of all babies have a ‘stork bite’ mark.
• The marks usually disappear by 12 months of age, if not earlier.
• The mark at the back of the neck may stay for longer, but it is usually covered by hair and out of sight.
• Occasionally, marks on the forehead, side of the nose and upper lip may persist longer.

Mongolian spots

The typical characteristics of Mongolian spots include:

• They are bluish, irregular flat patches.
• They are mainly found on the back and bottom, although any area can be affected.
• There is no thickening or change to the feel of the skin.
• They are more common in babies from Asian and African ethnic groups who have darker skin colouring.
• They are harmless and become less obvious as the child grows.
• They can be confused with bruises.

Haemangioma of infancy or ’strawberry mark’

Another name for a strawberry mark is haemangioma of infancy. The typical characteristics include:

• They are red, raised and lumpy areas.
• They usually appear at around one to four weeks of age, then get bigger – sometimes quite quickly – for a few months.
• They stop growing between six and 12 months of age, then gradually disappear over the next few years.
• The skin of the birthmark is as strong as any other skin. It might rarely bleed if knocked hard or scratched, or develop an ulcer on the surface and need to be treated.
• Sometimes, the strawberry mark may grow on the face, near the eye. If it pushes on the eye, it needs urgent treatment or the child may not develop normal vision.

It is not possible to predict exactly how big a strawberry mark will grow before it stabilises and eventually starts to disappear. If diagnosed within the first weeks of life, laser therapy will most likely make the marks disappear. While expanding, a number of medications can be used to stop its growth.

If the haemangioma has already stopped growing, then no treatment may be necessary. Some will regress and disappear spontaneously by the age of two years, about 60 per cent by five years, and 90 to 95 per cent by nine years. I If they are large, disfiguring, block vision or start to ulcerate, they should be referred to a dermatologist for immediate treatment.

Café au lait spots

• Café au lait macules are flat, roughly oval-shaped light brown (milk-coffee coloured) spots.
• They may be present at birth or appear in early childhood.
• Many children have one or two of these – they are not signs of a health problem.

If your child has more than three or four spots, check with your doctor, as they can sometimes indicate a rare disease, such as neurofibromatosis.

Melanocytic naevus (moles)

The typical characteristics of melanocytic naevus (congenital and acquired), also known as moles, include:

• A congenital melanocytic naevus is a brown spot that is present at birth or in the first year of life.
• Acquired melanocytic naevi are much more common and develop in childhood from around the age of two.
• Some are large dark brown, blue or black birthmarks that sometimes grow dark hairs.
• Some are raised and lumpy, while others are flat and irregular in shape.

It is very rare for melanoma cancer to develop in such lesions later in life and even rarer in childhood. A sign that cancer may be developing includes changes of the skin on or around the mark.

Capillary malformation (port wine stain)

The typical characteristics include:

• They are flat, large or small areas of skin that are pink or purple in colour
• They are usually present from birth and the colour gets darker (from pale pink to deep red-purple) as the child grows.
• They may thicken and become lumpier around and after puberty.
• The marks are often on the face, sometimes just on one side. They may have a clear edge along the middle of the face, but they can appear anywhere on the body.
• Some of these marks, particularly on the face and leg, can be associated with other problems.

Treatment for birthmarks

Most birthmarks are harmless but permanent. The only ones that fade with time are Mongolian spots and haemangiomas of infancy.

Treatment may include:

• Haemangioma of infancy – sometimes, a strawberry mark will grow over an eye or may block one side of the nose, ulcerate or cause other problems. In these cases, they can be treated with a medication called propranolol.
• Melanocytic naevus – sometimes, these will need to be removed surgically, because the child finds the mark distressing. Others that start to grow, often during the teenage years, need to be carefully watched. If the mark changes, get it checked by your doctor.
• Capillary malformations – these don’t go away by themselves. It is best to have expert advice about laser treatment early, because their appearance can affect a child’s feelings about themselves. Laser therapy may give good results.

Birthmarks may be a symptom

Very occasionally, port-wine-stain birthmarks may indicate the presence of a rare underlying disorder, including:

Sturge-Weber syndrome

Symptoms include a port-wine-stain birthmark on the upper eyelid and forehead, and abnormalities of the brain (and sometimes of an eye).

Klippel-Trenaunay-Weber syndrome

Symptoms include a port-wine-stain birthmark on the leg (usually). The bones, muscles and other tissue near the birthmark grow larger than the other normal limb.

Where to get help

• • Your GP (doctor)
  • Dermatologist
  • Paediatrician
  • The Australasian College of Dermatologists Tel. (02) 8765 0242