This page explains about laser treatment for birthmarks and what to expect when your child comes to Great Ormond Street Hospital (GOSH) to have this procedure.
Laser treatment, with a pulsed dye laser, is currently the treatment of choice for improving the colour of a port wine stain.
It may also help reduce the risk of a ‘cobblestone’ effect that can develop in adulthood. When laser treatment is carried out at a specialist centre, which is experienced in dealing with vascular birthmarks in children, the results can be excellent and the side effects minimal.
How does laser treatment work?
Laser treatment uses a narrow beam of light that is absorbed by the red colour in the blood vessels in the port wine stain making it lighter in colour. This is called selective photothermolysis, which means that the specific area (selective) of tissue containing blood vessels is treated (lysis) using light (photo) that in turn produces heat (thermo).
Each time the laser beam touches the skin, it treats a small area only a few millimetres across. We call this a laser ‘dot’ and most children have lots of ‘dots’ in one laser treatment session.
How long does laser treatment take?
In our experience, the best results occur when a series of treatments, usually between four and six, take place over a few years. The length of each treatment session varies according to whether your child has treatment under general anaesthetic or local anaesthetic and the characteristics of their birthmark.
The first stage in the treatment process is usually a ‘test patch’, which shows how well your child’s birthmark responds to the laser. Most of our children have a test patch, but if the port wine stain is very small, it might not be needed.
The test patch involves having a few laser ‘dots’ at a much lower laser energy on a normal area of skin and a few on the birthmark itself. The ‘dots’ at a higher laser energy can be uncomfortable (children have told us that it feels like being flicked with a rubber band) so the area of skin being tested is usually numbed first using local anaesthetic cream. Some laser machines have a cooling jet of spray or a cool air blower before each ‘dot’. The treated area will be covered with a cold dressing afterwards to make it more comfortable.
As with all laser treatment, your child’s skin will need to be looked after carefully after the test patch. Please read our information on caring for your child after skin laser treatment for further advice. Afterwards, when the results are more noticeable, you will need to come back to the hospital so the results of the test patch can be checked and any future treatments planned. This is usually three months after the initial test patch.
Once your child has had a test patch and it has shown that laser treatment will help, they can start to have regular treatment sessions. These involve many more ‘dots’ than the test patch, so some children have laser treatment under a general anaesthetic. Children can also have local anaesthetic treatment if the size of port wine stain, its location on the body and the number of ‘dots’ planned makes this practical.
What happens afterwards?
If your child had laser treatment using local anaesthetic, they will be able to go home immediately afterwards. If your child had a general anaesthetic, they will need to stay on the ward for a few hours afterwards until they have woken up completely and eaten some food.
Your child’s skin will look bruised and sore after each laser treatment. Their skin will need to be looked after carefully for two to three weeks after each appointment. Your child will also need to wear a high factor sunblock for the whole course of the treatment, as sunlight can darken birthmarks making them harder to treat. Please read our information on caring for your child after skin laser treatment for further advice - a copy of this information will be given to you after each treatment session.
Last reviewed by Great Ormond Street Hospital: April 2012
Ref: 2012F0339 April 2012
Compiled by the Birthmark Unit in collaboration with the Child and Family Information Group, GOSH.
This information does not constitute health or medical advice and will not necessarily reflect treatment at other hospitals. If you have any questions, please ask your doctor. No liability can be taken as a result of using this information.