Moles are common and come in all kinds of different shapes, sizes and colours. But what exactly are they? And how do you know when to get them checked? We chatted with Vhi Consultant Dermatologist Dr Rupert Barry to understand more about moles, how to monitor them, and when to take action.

What is a mole?

First and foremost, Dr Barry notes that it’s important to understand that moles are a totally normal part of the skin. ‘Some people think any mole is a bad thing, but this isn’t the case.’ Our skin contains pigment cells called melanocytes, and when a collection of melanocytes group together, they create a mole.

There is a large spectrum when it comes to moles, and what is ‘normal’ depends on the person. For instance, some people may have very few moles (less than 10), while at the other end of the spectrum, there is a condition called dysplastic mole syndrome, whereby a person can have more than a hundred moles, and they all look different from one another in terms of size, shape and colour. When looked at using a dermatoscope, their moles may look abnormal in appearance and architecture. In general, most people have a certain pattern of moles—their moles all look similar. But for people with dysplastic mole syndrome, there is no pattern—all their moles look different from one another. People who have dysplastic mole syndrome have a slightly higher risk of developing melanoma.

What is a melanoma?

A melanoma is a cancer that develops either from a pre-existing mole or from apparently clear skin where there is no mole. It forms within the pigment cells called melanocytes. In melanoma, the cells grow and become autonomous or independent of the regular growth control mechanisms of the body and immune system and develop into a tumour.

Are we born with moles?

If a mole is present at birth or develops within the first six weeks of life, it is called a congenital mole. These can vary in size, defined as small up to ‘giant’, which is greater than 20cm in diameter. The vast majority of congenital moles are benign and patients should not be overly concerned about them once they have been seen by their doctor. Like all moles, the person should keep an eye out for any unusual change in size, shape or colour, though congenital moles will undergo a normal maturation process throughout years.

Are moles genetic?

In general, we develop moles from early childhood (or birth) until early middle age (approximately late 40s). Some people have lots of moles, and when asking parents or siblings if they have any moles, we realise we tend to ‘genetically’ inherit our likelihood of having lots, a normal number of, or just a few moles. However, a person can have lots of moles while their parents have only a few moles, so the genetics of “how many moles will I or should I have” is complex and non-linear.

Are there different types of moles?

We can classify what type of mole someone has depending on where it sits in the skin. The top layer of our skin is called the epidermis, and the next layer is called the dermis. Moles are generally dotted along the junction of the epidermis and the dermis, but they can also be within the dermis. These moles within the dermis are called intradermal moles. Intradermal moles are usually a similar colour to your skin because they don’t have much pigment in them. They are very common, and are often seen on people’s faces as small, skin-coloured, bumpy moles, and are completely benign.

Another type of mole are those that appear on the ‘acral’ areas of the body. These acral sites are also known as ‘special sites’, which include:

• the soles of your feet
• the palm of your hands
• your scalp
• buttocks
• breast area (and that applies to all genders)

When you get a mole in these areas, it may look much different from your other moles, and again, the same rules apply—has the mole changed size, shape or colour? If in doubt, you should ask your medical practitioner to examine the mole(s) for you.

How to check your moles

Checking your moles every three to four months is advisable. Using self-observation, Dr Barry highlights that we need to become aware of the ‘pattern’ of our moles. Our moles will often have similar size, shape and colour. The moles on your upper limbs might look different from the moles on your lower body, but the moles on each body site should look quite similar—following a similar pattern. What you need to look out for are new moles that don’t fit the pattern of others on your body.

As Dr Barry puts it, ‘you’re looking for the new or changing mole that looks like the ugly duckling. A mole that is new or has been changing either in size, shape, or colour, and it stands out. It doesn’t fit in with the others.’

Sometimes, after exposure to intense sunlight, some of your moles might become raised, red and irritated. This can be a normal response to intense sunlight exposure, but it should settle down a few weeks after the intense sunlight exposure. If the changes persist, you should seek a medical opinion.

If one of your moles changes colour to a ‘pinky’ colour and there has been no recent irritation of the overlying skin to cause such a change in colour, then you should seek a healthcare provider’s opinion.

The ABCDE method

A dermatologist will often evaluate a mole using the ABCDE system, which is useful for your own self-evaluation.

• A stands for asymmetry; is it asymmetric in shape, colour or general structure?
• B stands for border; is the border of the mole irregular?
• C stands for colour; does it have more than two colours? Keep in mind that lots of benign moles will have more than two colours, so you must consider this in context.
• D stands for diameter; is it greater than 6mm? Again, this needs to be considered in context, as lots of benign moles can be larger than 6mm in diameter.
• E stands for evolving; is it changing in size, shape or colour?

It’s important to understand that the markers of the ABCDE system are all just pointers, and that answering yes to any of them does not mean your mole is a cause for concern. Simply contact a healthcare provider to check the mole for you if you are concerned about a recent unusual change in your mole or if it has become the ‘ugly duckling’ mole.

Hopefully, this guide has helped you understand what’s normal for moles and when you should see your healthcare provider. What’s important is knowing what is normal for you and talking to your healthcare provider when a mole doesn’t follow the pattern of the others you have or if you’ve never had a mole before and one develops. Though, as Dr Barry put it, ‘moles are a completely normal part of life’. You can learn the pattern of your moles and self-evaluate every three to four months. If you find a new or changing mole that stands out, speak to your healthcare provider to find out more.

This content is for information purposes only and is not intended or implied to be a substitute for professional medical advice, diagnosis, or treatment. Always seek advice from your GP or an appropriate medical professional if you have concerns about your health, or before commencing a new healthcare regime. If you believe that you are experiencing a medical emergency call 999 / 112 or seek emergency assistance immediately.

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