The ABCs of moles

Ever wonder if you should be checking your moles? Or your childrens’ moles? Or what to look for?

Worrisome features in children’s moles are different from those in adults. Read on for a set of guidelines for skin self-checks in both adults and children.

A set of rules to assess moles for melanoma risk in adults and older children (older than 10) is the “ABCDE” rule. Not every mole that meets one or more of these criteria is worrisome, but moles that meet the ABCDE criteria deserve to be checked by a doctor:

  • A: Asymmetry – this describes moles that don’t look the same on both sides if you imagine dividing them in half
  • B: Border irregularity – a border with notches or an irregular outline
  • C: Colour variation – moles with more than one colour
  • D: Diameter – greater than 6mm (the size of a pink eraser on the tip of a pencil)
  • E: Evolution – a mole that is changing rapidly, for example from one month to the next, or changing differently or faster than other moles

Melanoma is extremely rare in childhood. A modified ABCD rule was developed for pre-pubertal children (10 and younger) in 2013, as melanoma can present differently in this age group and can be missed by the traditional ABCDE above:

  • A: Amelanotic – the bump is not pigmented (i.e. not brown or black), but is skin-coloured, pink or red
  • B: Bleeding, bump – a new, non-resolving bump or bleeding skin lesion
  • C: Colour uniformity – melanoma in children tends to be a single colour, in contrast to adult melanoma which often has multiple colours
  • D: De novo, any diameter – a new lesion, not necessarily larger than 6mm

Change remains an important feature. Many childhood melanomas are rapidly evolving or growing. It is also helpful to keep in mind the “ugly duckling” rule and to have any mole checked that is behaving differently from the rest.

Some helpful hints for managing your moles:

  1. Avoid sun exposure. Ultraviolet (UV) exposure, both with and without sunburn, is linked with the development of more moles in children. We also know that the sun can cause changes in moles that can lead to melanoma.
  2. Know your moles. If you have moles on your back, take a picture that you can compare to when checking.
  3. Watch for change. Moles do change throughout life- they can grow, and sometimes become more bumpy. These changes usually happen slowly over the course of years, and happen similarly in multiple moles.
  4. Watch for the “ugly duckling”. A mole that is changing faster than others, or meets any of the ABCD criteria, should be checked by your doctor.


This article is intended to provide general information and is not intended as a substitute for assessment and care from your doctor.

“Beauty begins the moment you decide to be yourself.”

Coco Chanel

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Dr. Kuritzky is pleased to offer her services in french and english.
Dre. Kuritzky est fière d’offrir ses services en français ainsi qu’en anglais.

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