When to Worry About a Mole: A Dermatologist’s Guide to Skin Checks

In Cyprus, where sunshine is a year-round companion, it’s more important than ever to keep an eye on your skin. In London and in my clinic here in Cyprus, I often see patients who are unsure whether a mole is harmless or something more serious. 

So how do you know when to be concerned? 

The “Ugly duckling”  Sign

One of the most important clinical principles we use is the “ugly duckling” sign — spotting the mole that looks different from all the others. It may be larger, have a different colour, or stand out in shape compared to your other moles.

Self-monitoring with ABCDE rule:

Use this simple guide to check your moles at home:

A - Asymmetry: One half of the mole doesn’t match the other.

B - Border: Edges that are irregular, notched, or blurred.

C - Colour: Uneven colour or multiple shades (brown, black, pink, blue).

D - Diameter: Moles larger than 6mm (about the size of a pencil eraser).

E - Evolving: Any change in size, shape, colour or new symptoms like itching or bleeding. Evolution is considered the most important sign.

For more information see the ABCDEasy guide from the British Association of Dermatologists.

When to See a Dermatologist

If you notice any of these signs, it’s best to have the mole examined by a dermatologist. In my clinic, I use dermoscopy – a specialised tool that magnifies and illuminates the skin- to evaluate lesions in detail.

Patients at higher risk, such as those with many moles or a family history of melanoma, often benefit from regular skin checks.

Mole Self-Check: Do’s & Don’ts

✔ Do:

• Check your skin monthly in good lighting, using a full-length and hand mirror.

• Learn the ABCDE rule and look for the “ugly duckling” mole.

• Pay attention to any new moles, especially after age 30.

• Ask a partner to check areas you can’t easily see (back, scalp).

• Book a dermatologist appointment if you notice changes.

✖ Don’t:

• Ignore a mole that’s changing in size, shape, or colour.

• Rely on online images for diagnosis.

• Assume a mole is harmless just because it isn’t dark.

• Delay seeing a doctor if a mole bleeds, itches, or feels different.

Why Early Detection Matters

Melanoma caught early is almost always curable. Left unchecked, however, it can spread quickly and become life-threatening.

Key takeaway: If you’re unsure about a mole, don’t wait- book a professional skin check.