Dear doctor, I'm worried about a mole on my back. How do I know if it's dangerous?

13 June 2017

Q: I have a mole on my back which I’ve started to worry about lately. I do put sun cream on it when sunbathing but am wondering if there are any signs I should look out for? How do I know if it’s dangerous?

A: Moles are a normal part of most people’s skin and can appear and develop during childhood until early adulthood.

As a dermatologist, I would recommend being sensible whilst in the sun as the skin (and moles) can be damaged in different ways - not only by sun burning but also by the love of a lifelong baseline tan. Sunbeds are not always regulated and can sometimes feature higher levels of ultraviolet rays (the rays that tan and burn you) making them particularly dangerous.

All EU sunscreens are tested. I’d recommend factor 30+ SPF (UVB protection) and good to high UVA protection (whichshould always be labelled) applied as directed. For vitamin D you only require a low level of sun exposure when the sun is weaker (early or later in the day) a few times a week, so not enough to be turning you into a prune!

The key to monitoring moles is change. If a longstanding mole is changing it should be reviewed by a specialist. Many national organisations have produced handy tips on what to look out for. The ABCD is a widely used rule which advises people to get their moles checked if they exhibit any of the following signs:

  • A mole is becoming Asymmetrical or more irregular
  • Border is becoming uneven
  • Colour is changing or increasing
  • Diameter (size) is growing

Some brown spots that develop later in life, also known as "wisdom spots" are usually nothing to worry about but it can be examined by a trained eye for reassurance. A dermatologist will be able to talk through the treatment options available to you if you wish to have them removed.

Dr Hywel Cooper is a Consultant Dermatologist practising at Spire Portsmouth Hospital. 


The content of this article is provided for general information only, and should not be treated as a substitute for the professional medical advice of your doctor or other health care professional.

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