When should you see a dermatologist about a mole?

First: what is a mole?

A mole or melanocytic nevus is a benign proliferation of melanocytes, the cells that produce melanin.

They can be: brown, black, pink, skin-coloured, flat or raised.

And they can present different shapes and sizes.

The vast majority require no treatment at all.

But certain changes may make a dermatological evaluation advisable.

The ABCDE rule

A simple way to monitor moles is the well-known ABCDE rule.

A — Asymmetry. One half of the mole does not match the other.

B — Border. The borders are irregular, poorly defined or jagged.

C — Colour. Several colours exist within the same lesion. For example: light brown, dark brown, black, red, white or blue.

D — Diameter. Traditionally we pay attention to lesions larger than about 6 mm. But this must be interpreted with care. A melanoma can measure less than 6 mm. That is why size should not be used as the sole criterion.

E — Evolution. This is probably the most important letter. A mole: grows, changes shape, changes colour, becomes more raised, starts to bleed or simply behaves differently. Evolution is one of the main reasons to seek a dermatological evaluation.

What is the 'ugly duckling' sign?

It is a very useful concept.

Most moles on the same person tend to share certain characteristics. Similar colour. Similar size. Similar appearance.

But sometimes there is one that simply does not look like the others. That is the 'ugly duckling.'

And it deserves attention. Not because it is automatically malignant. But because it is different from that person's usual pattern.

Is a new mole cause for concern?

Not necessarily. New moles can appear throughout life.

But a new lesion in adulthood deserves more attention than a lesion that has been stable for many years.

Especially if it also: grows, changes, or displays any atypical feature.

What if a mole itches?

Itching alone does not mean melanoma.

A mole can become irritated from friction. It can become inflamed. It can coincide with a dermatitis.

But if a mole that itches is also changing, bleeds, or shows other new signs, it deserves evaluation.

What if it bleeds?

A mole that bleeds after being scratched or traumatised does not automatically mean cancer.

But if it bleeds spontaneously, repeatedly, or with minimal trauma, it is worth having it looked at.

Especially if it also shows changes in colour, shape, or size.

What if it forms a crust?

A lesion that repeatedly forms a crust, ulcerates, or seems to 'heal and open up again' needs evaluation.

Not all skin cancers present as a dark mole.

Some lesions may appear as: crusts, reddish patches, persistent sores, or wounds that do not heal.

What about a very dark mole?

Dark color alone does not determine malignancy.

There are heavily pigmented benign nevus. And there are poorly pigmented or even amelanotic melanomas.

What matters is the whole picture: asymmetry, borders, color, evolution, comparison with the rest of the moles, and clinical context.

What if it has hair?

Having hair inside a mole does not confirm that it is benign.

Hair can appear in benign nevus, but that detail does not replace an overall evaluation.

We do not use a single characteristic to make a decision.

Should we have all our moles checked every year?

There is no single frequency that applies to everyone.

How often you need check-ups depends on your individual risk.

For example: number of moles, type of moles, phototype, personal history, family history of melanoma, sun exposure, previous sunburns, and other factors.

Some people need more frequent, closer follow-up. Others do not.

What does a mole check consist of?

A mole check consists of evaluating skin lesions in a systematic way.

It is not simply a matter of looking at the mole that is causing concern.

We often review the full set of lesions because comparing them with one another provides useful information.

Moreover, some suspicious lesions are not necessarily the ones the patient was most worried about.

What is dermatoscopy?

Dermatoscopy is a fundamental tool in the assessment of pigmented lesions.

We use a dermatoscope to observe structures that we cannot adequately see with the naked eye.

It allows us to study: pigment patterns, vessels, internal structures, and other elements that help differentiate benign lesions from those that require further study.

It does not replace clinical diagnosis. It enhances it.

Can a photograph be enough?

A photograph can help. Especially for tracking changes over time.

But it is not always enough.

The lighting. The focus. The distance. The camera's colour rendering. All of these can alter the appearance of a lesion.

And a conventional photograph does not show the same detail as dermatoscopy.

That is why, if a lesion is changing or raises doubts, direct examination remains important.

When is a biopsy needed?

When a lesion has suspicious characteristics or we cannot establish a sufficiently confident diagnosis through examination.

A biopsy allows the tissue to be studied under a microscope.

In certain lesions suspicious for melanoma, complete excision of the lesion may be indicated in order to carry out an appropriate histological study.

The definitive diagnosis of melanoma is histological.

Can a mole be removed with a laser?

Here we need to be careful.

A doubtful pigmented lesion should not simply be destroyed with a laser before its diagnosis is known.

Why? Because if we destroy the tissue, we may lose the opportunity to analyse it properly.

That is why: diagnosis first. Afterwards, if it is benign and there is an aesthetic indication, we can consider options.

What about moles on the scalp?

These should also be checked when they show changes.

The scalp is an area that many people cannot easily see themselves.

That is why it can be helpful to ask another person for assistance, or to have the area examined during a dermatological consultation.

What about moles on the soles, palms, or genitals?

Benign lesions can also exist in these areas.

However, acral lesions and genital lesions have specific patterns, and some may require dermatoscopic evaluation.

We should not think that melanoma only appears in areas heavily exposed to the sun.

And what about under the nails?

Longitudinal pigmentation of a nail can have multiple causes.

Many are benign. But certain characteristics need to be evaluated.

That is why there is a difference between a cutaneous mole and ungual melanonychia, even though both can be related to melanocytic pigmentation.

Which people are at higher risk?

Among the known factors are: fair skin, severe sunburns, a large number of nevus, atypical nevus, a family history of melanoma, a personal history of melanoma, and significant ultraviolet exposure.

But a person with none of these factors can also develop melanoma.

That is why risk guides surveillance, but does not replace the observation of changes.

What role does the sun play?

Ultraviolet radiation is an important factor in the development of various skin cancers.

Photoprotection reduces accumulated UV damage.

That means: sunscreen, clothing, a hat, shade, and avoiding repeated intense sun exposure.

But prevention does not completely eliminate the risk. That is why we still need to know our own skin.

What signs justify a consultation?

I would sum it up like this.

Consult a dermatologist if you have a mole that is changing. If a new lesion appears and keeps evolving. If it is clearly different from the others. If it has multiple colours. If its edges become irregular. If it bleeds repeatedly. If it forms a persistent crust. If it does not heal. If it starts to itch or hurt persistently alongside other changes. Or simply if you have doubts because it no longer looks like the same mole it used to be.

And what if the dermatologist says it is benign?

Then that is also a worthwhile consultation.

Not everything we examine needs treatment.

Sometimes the conclusion is: 'This is benign. Nothing needs to be done.'

And that is exactly what we want to know.

What I want you to remember

Most moles are benign. You do not need to look at them every day in fear. But it is worth getting to know them.

Because the most important question is not: 'Is this mole dark?' It is: 'Is this mole changing?'

Remember: ABCDE. Asymmetry. Border. Colour. Diameter. Evolution. And add one more idea: the ugly duckling.

If a mole is different from the rest or is changing, have it checked.

Because a mole check does not only serve to find a problem. It also serves to confirm when a lesion is completely benign.

And in preventive dermatology, knowing when there is nothing to worry about is just as important as detecting what does need treatment.