We did a study across many years where we looked at the colour of CMN overtime in the same people. We had a large number of people, took photographs, and recorded the colour of their CMN with a colour measurement machine. We looked at what happened to their CMN, in particular we looked at the CMN of people who had had it lasered or treated by another type of removal, like dermabrasion or curettage. These are techniques where the top of CMN is removed, scraped away and the bottom is still there. Laser does the same, it takes away the top and leaves the rest.

We were particularly interested in people who had been treated in part, part of their CMN had been treated and the other part had not. This happens, for example, when sensitive areas in the nappy area are not treated and the other parts are. However, the CMN is joined up, so in those cases we were able to show that laser therapy did not make any difference to the colour in the long run in the area that was lasered. There was a temporary lightening but then the colour of the CMN would come back, not always as dark as it had been at birth. When we looked at the parts that were not lasered, they had ended up exactly the same colour as the lasered area.

We realised the eventual colour of the CMN is actually dictated by your body’s own skin colour. If you are someone with a darker skin tone your CMN will be darker at birth and will probably stay dark. If, however you are somebody who is born with lighter skin then your CMN is often very dark at birth but will gradually lighten overtime. It looked like these treatments had made the CMN lighter, but this lightening would have happened anyway.

We don’t think any of these treatments work for colour, we don’t think they are good treatments for CMN.

We do not have data on whether these treatments can reduce lumps or bumps or prevent a CMN from developing complications or cancer.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now. You can watch the full recorded session here.

The decision to have surgery has to be made on an individual basis, and very much depends on whether the surgeons think they can improve the appearance.

In cases of very large CMN, survery if often not possible. iN other cases, the following points should be considered:

  • Many CMN will lighten spontaneously to at least some degree over a period of year. This can be monitored with repeat photographs.
  • Surgery has not been shown to reduce the risk of melanoma in the child.
  • Early surgery has not been shown to be advantageous. No routine surgery should take place before the age of 1 years.
  • The site of the CMN is very important. For example, the child may get more benefit if a CMN on the face is removed, compared to one hidden on the scalp.
  • The size of a CMN is very important – we have found that children with larger CMN were less pleased with the cosmetic result than those with small lesions which could be completely removed.
  • The number of naevi is important, in particular if the child has a tendency to develop lots of new ones as this may reduce the benefit from removing some.
  • Whether you want your child to take part in the decision, in which case it is better to wait until your child is old enough to consider the options available.
  • What is involve in the type of surgery being offered – this will depend on the individual case.

If a CMN can be removed, for example by excision or serial excision (more than one operation but relatively straight-forward), the cosmetic benefits may easily outweigh the small risks associated with any operation. However, if a CMN is in a difficult place for removal, or if it is too large ever to be removed completely, then level of possible risk increases. It is very important in such cases, you should take time to decide about surgery, particularly to see if the CMN is lightening over time.

Laser therapy cannot be used to treat CMN. It will often lighten the colour, but this is a temporary phenomenon, and the CMN will gradually (or sometimes rapidly) grow pigment again. Sometimes it appears that the colour after repigmentation is lighter than it was at birth, but we now know that this is because in that individual the CMN was going to lighten anyway, and the final colour is connected the person’s own hair and skin colour, not to the colour it was at birth (or to any longterm help from laser). The same applies to dermabrasion or curettage, which are other superficial removal techniques.

Laser hair removal will work better if your skin is light and your hair is dark. In a CMN, the background colour is usually dark and the hair is dark or very similar at least. There’s a risk that when the laser is applied to the hair that it will also burn the skin itself which we don’t think is a good idea.

We wouldn’t recommend having laser hair removal for CMN, we don’t think it would work very well. It is always possible to get opinions from a laser hair removal professional. If you wanted to do it, we would strongly suggest using a small test patch to see if it was going to work without burning the skin. Many laser therapists will think that laser would be good for the whole CMN, in reducing colour, but we know that’s definitely not the case.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now. You can watch the full recorded session here.

Everybody’s CMN is unique, meaning they vary in size, texture and shape. CMN may change over time. Changes within CMN cannot be defined as normal or abnormal without the medical assistance of a doctor who will assess the changes. If you notice changes within your CMN which you are unsure about, please see your doctor or dermatologist.

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