The lowdown on birthmarks

Birthmarks are common in babies with 20-50% of babies having them. Here we take a look at what they actually are and why some babies have them.

What are birthmarks?

Birthmarks are coloured marks on the skin that are visible against the skin. It’s common to have a birthmark at birth but they can also develop soon after birth.

There are more than one type of birthmark. 

The most common type of birthmark is pigmented birthmarks. The cause of a pigmented birthmark is a collection of tiny blood vessels just under the skin.

What do pigmented birthmarks look like?

A pigmented birthmark will be tan or brown-coloured skin marks. Caused by clusters of pigment cells they are often referred to as café-au-lait spots. If it is flat, blue-grey in colour it is referred to as a Mongolian spot.

The second common type of birthmark is vascular birthmarks. These are caused by irregularities in the way the blood vessels have formed.

Mongolian spots  

These flat blue-grey bruise-like marks and tend to be on a baby's back or bottom. They usually appear at or within a few weeks of birth and tend to be gone by the time they are four or five years old. These marks are more common in Asian-origin or African-origin babies.

Congenital moles 

Also called congenital melanocytic naevi these can be visible at birth and appear brown in fair-skinned babies or almost black in dark-skinned babies. Some can be raised and with hair. They are often on a baby's body, usually the back. They can shrink as your baby gets older but can darken during puberty. They can be surgically removed but most are best left alone.

What do vascular birthmarks look like?

A vascular birthmark will appear red, purple or pink in colour. In some cases if the affected blood vessels are particularly deep, the birthmark may look blue.

They most commonly occur in the face and neck area. There are several types of vascular birthmarks and here are the most common.

Strawberry haemangioma 

Often described as a raised red strawberry mark. These commonly appear on a baby's skin within a few days or weeks of birth. They tend to appear on a baby’s head or neck, but can be anywhere on the body. They tend to grow quickly in the first six months and generally go by the age of about seven years old.

Cavernous haemangioma

This type of birthmark appears lumpier and more purple in appearance and is deeper in the skin than a strawberry mark. They affect around 5% of babies and are more common in girls. It tends to grow fast in the first six months, before slowing down and shrinking by the age of around 18 months. They should be gone by the time your baby reaches five to seven years old.

Port wine stains

Port wine stains are so called as they are flat red or purple marks and can vary in size from a few millimetres to several centimetres. 

If you’re baby has a port wine stain it is likely to be on one side of your baby's face, chest or back. If they have one that is fairly light in colour chances are it may fade, but they tend to get bigger as your baby grows, getting deeper in colour, and more raised and bumpy and become sensitive to hormones and become more noticeable around the time of puberty.

Salmon patches

Often called stork marks or angel kisses. These are flat, pale pink patches that tend to be on a baby's eyelid, or on the forehead or between eyebrows or even at the back of the neck. These tend to fade and disappear completely as your baby grows. On the forehead they may take up to a few years to fade and ones on the back of the neck last longer.

Do I need to do anything about my baby’s birthmarks?

Many birthmarks babies are born with or develop at a young age are harmless and don't need any treatment. Some fade over time, but others including port wine stains will stay if not treated.

If your child has a troubling birthmark, talk to your doctor or ask for a dermatologist referral. Doctors may suggest a wait and see approach but some experts challenge this in favour of earlier intervention so find out your options and all you can about the type of birthmark.