Skin

Checking your skin: the ABCDE rule

Melanoma is a type of skin cancer that develops from melanocytes, the pigment cells that help protect the skin from ultraviolet (UV) light. It can start in normal-looking skin or in an existing mole. In the US, about 100,000 people are diagnosed every year. It is more common in people with fair skin and after 50, but it also occurs in young adults.

When melanoma is found while still localised, about 99% of people are alive 5 years later, so noticing changes early really matters. Exposure to UV light greatly increases the risk: avoid sunburn and long sun exposure, and use sunscreen.

The USPSTF found too little evidence to recommend routine skin exams by a clinician for everyone. If you have many moles, fair skin, or a personal or family history of melanoma, ask your physician whether regular skin checks are right for you.

The ABCDE rule

• A – Asymmetry: the two halves of the mole don’t match.
• B – Border: some edges are irregular or poorly defined.
• C – Colour: uneven, with areas of different shades.
• D – Diameter: larger than 6 mm.
• E – Evolving: the mole is growing, changing, or becoming raised.

Also look out for a mole that looks different from all the others (the “ugly duckling”), an unusual mark on your skin or nails, or a sore that doesn’t heal, scales or bleeds.

How to check

Ideally after a shower or bath, in a well-lit room. You will need a full-length mirror, a hand mirror, a comb, a ruler and your phone camera. You can do it alone or with someone’s help.

1. Your scalp, parting the hair with the comb.
2. Your face, ears, nose and inside your mouth.
3. Your neck, chest and upper body, including under the breasts.
4. The back of your neck and your whole back, using the hand mirror.
5. Your armpits, arms and hands, including between the fingers and under the nails (look for dark stripes).
6. Your genitals, buttocks, the front and back of your thighs, lower legs and feet, including the soles and between the toes.

If a mole looks suspicious, take a photo with a ruler next to it and book an appointment with your physician.

This article gives general information and doesn’t replace advice from your physician. Want to know which screenings apply to you? Take the ScreenMe questionnaire.