Test yourself: Could you spot a skin cancer? Never miss a melanoma.

Test yourself: which do you think are malignant skin cancers? Click to enlarge. Answers at bottom of post.

If you ever doubted humankind’s ability to do great things for our planet, just look at the sky. Or rather, look toward the ozone layer high in the stratosphere. If you cast your mind back, you will remember that there was a lot of talk of the ‘hole in the ozone layer’ brought on by CFCs in the eighties and early nineties. Today, no one seems to mention it anymore, even though climate change is still a very hot potato. This fragile ozone layer is the Earth’s way of blocking out the worst of the sun’s harmful UV rays and without it everyone would die of cancer. But ever since all the world’s nations outlawed all CFC-releasing chemicals in 1987 – such as those in fridges and aerosol cans – ozone layer damage has stopped. Better than that, the ozone layer is now actually repairing itself and the ‘hole’ is shrinking.

It’s an incredible achievement but, strangely enough, rates of skin cancer continue to sky-rocket. Six people die of malignant melanoma – the most feared of skin cancers – in the UK every day. Too much time in the sun or under a sun bed are the main causes. Everyone would do well to visit Cancer Research UK’s SunSmart website (www.cancerresearchuk.org/sunsmart) for a summer refresher. And while I have written about sun safety before, it is the first time I have done so while having a suspected malignant melanoma apparently growing on the top of my foot.

At the time of writing this I am awaiting an emergency appointment with a dermatologist, who will take a closer look at this suspicious-looking mole. I first noticed it a little over a week ago while walking in flip-flops and, thanks to my medical background, knew exactly what it might be. It is darker than most skin blemishes has an uneven in shape, irregular edges and – most importantly – it definitely wasn’t there last summer.

As a doctor, the tell-tale signs were obvious to me, but it isn’t rocket science and anyone can know what to look. If you think you have a new mole or skin change, just think A, B, C, D, E. The warning signs that should prompt an urgent doctor’s appointment include any one of the following:

• Asymmetry – if you can draw a line through the middle and the two halves don’t match
• Border – the edges look uneven or notched
• Colour – there are a variety of colours in it; it is patchy or shaded
• Diameter – melanomas are often larger than about 6mm (the size of an eraser on the tip of a pencil), but not always
• Evolving – a mole that changes in colour, size, or bleeds, becomes itchy or looks inflamed

Please remember to stay safe in the sun this summer. Go in the shade between 11-3pm, cover up with a t-shirt, wide-brimmed hat and sunglasses, and regularly apply at least SPF15 sunscreen (with UV-B protection). And don’t forget to protect those areas you usually forget, like the ears, eyelids, back of the neck, lips… and feet.

Thanks for reading – all opinions expressed are my own. Never delay seeinh a medical professional about any new or growing mole. Feel free to add your thoughts in the comments below but note that I do not give any personal medical advice. Follow @realdoctorstu

Answers: A, D, E and H are all melanomas. The others are benign moles. How did you do?