The 10 deadly signs of skin cancer that are NOT moles. As temperatures climb, experts reveal the tell-tale marks, scabs and spots you should never ignore. They’re so easy to miss

It is no exaggeration to say America is in the grip of a skin cancer epidemic.

More people are diagnosed with skin cancer in the US each year than all other cancers combined.

According to the American Academy of Dermatology, an estimated 5.4 million cases of basal cell and squamous cell carcinoma are treated annually in more than 3.3 million Americans.

Meanwhile, melanoma – the deadliest form of skin cancer and one of the most common cancers in young adults – is expected to be diagnosed in more than 100,000 Americans this year, with around 8,000 deaths projected.

Yet experts stress that the vast majority of skin cancers are preventable.

The warning comes as much of the country braces for another stretch of extreme summer heat, with temperatures expected to climb into the 90s and even exceed 100°F in some areas this week.

Doctors fear the burden could continue to grow as Americans spend more time exposed to intense ultraviolet radiation.

So, as millions head outdoors to enjoy the sunshine, how can you reduce your risk of developing the disease? And what are the warning signs and symptoms everyone should know?

Watch out for white patches and disappearing moles

Most melanomas are spotted because they appear as a new mole, or a change in an existing one – usually in areas exposed to the sun, says consultant dermatologist Dr Christopher Rowland Payne.

But a mole that shrinks or even disappears can be a far less obvious – and often overlooked – warning sign.

‘Amelanotic melanomas may appear pink, or essentially clear and colourless, making them incredibly difficult to spot,’ Dr Rowland Payne explains.

This can delay diagnosis, with potentially life–threatening consequences. When caught early, melanoma is almost always curable – but it becomes far harder to treat over time.

To help detect these more unusual cases, he advises checking your skin regularly for any subtle changes – including in moles you already have.

‘Dandruff’ could be a cause for concern

Skin cancer can develop anywhere on the body – but it is often hardest to detect on the head and scalp because it is out of sight.

While many people remember to protect their face from harmful UV rays, the scalp remains one of the most overlooked – despite being highly vulnerable to sun damage.

Persistent tenderness, redness around the hairline, or even what seems like stubborn dandruff should not be dismissed, experts warn – particularly if symptoms do not improve.

‘It’s not uncommon for people to burn along their hair part, but many don’t notice until it starts to peel,’ Dr Rowland Payne explains.

‘By then, the damage is already done.’

The problem is that this can easily be mistaken for a dry scalp or dandruff, when in reality the skin may be shedding as part of an inflammatory response triggered by sun damage.

While dandruff itself is not a sign of skin cancer, a persistently flaky patch in one area can be.

Key warning signs include large or uneven flakes, discolouration of the scalp, or bleeding.

For this reason, it is worth spending a few extra minutes protecting these areas – applying sunscreen along your hair part and wearing a hat, Dr Rowland Payne advises.

Don’t dismiss scabs on the scalp 

Dry, scaly patches of sun-damaged skin – known as solar keratoses – are not always cancerous, but they carry an increased risk of developing into skin cancer.

‘Older bald men who have scabs on their scalps should really have these lesions checked by a doctor,’ Dr Rowland Payne says.

‘They may seem harmless, but any solar keratoses should prompt a medical evaluation – especially if they are itchy, bleeding or sensitive.’

Sunspots can be harmless – but watch for changes

Most sunspots are benign, but in some cases they can signal lentigo maligna – a slow–growing form of melanoma.

They typically appear as blotchy patches on the face, ears or neck.

Look out for asymmetry or areas of darker pigment within lighter patches.

Black lines or bruising under the nail should not be ignored

‘A black mark under the nail is usually harmless, but melanoma can appear anywhere on the hands or feet – including the soles or beneath a nail,’ says Dr Rowland Payne.

This type of cancer – known as acral melanoma – is more common in people of Black or Asian heritage and can appear on the palms, soles, or under the nails.

As a result, it is often detected at a much later stage.

A new bump on your eyelid could be a problem

Eyelid cancers – including basal cell carcinoma – are relatively uncommon, but they do occur, particularly with cumulative sun exposure.

Between five and ten per cent of all skin cancers occur on the eyelid. Common warning signs include a smooth, shiny or waxy bump – or one that is firm and red.

A flat, skin-coloured lesion that resembles a scar can also be a tell–tale sign. Most of these cancers develop on the lower eyelid.

‘We all know sunglasses help protect our eyes from the sun, but they can also shield the eyelids – an area we often miss with sunscreen,’ Dr Rowland Payne says.

Even a ‘healthy tan’ could signal damage

There is no such thing as a safe or healthy tan. Tanning is caused by UV exposure, which triggers the skin to produce melanin in an attempt to protect itself from further damage.

Even people who tan easily may be at risk, so it is worth paying attention to the tone of your tan, Dr Rowland Payne says.

‘People who tan well are often lulled into a false sense of security,’ he explains.

‘This so–called ‘ability’ draws them into the sun, but in reality they may be repeatedly damaging their skin.

‘Pay close attention if your tan has a pink undertone, or if your skin becomes dry after time in the sun – both can be signs of damage.’

The bottom line: Avoid sunburn and wear SPF

‘We do not want people to stop enjoying themselves or stay indoors, but as temperatures rise we need to be more mindful of how long we spend in the sun,’ Dr Rowland Payne says.

Just one bad sunburn in childhood or adolescence can more than double the risk of developing melanoma later in life, according to Melanoma Focus.

‘Sunburn causes DNA damage, which not only increases the risk of melanoma but also suppresses the immune system that helps keep developing cancers in check,’ he says.

‘If you get burnt, you are effectively taking a double hit.’

To reduce your risk, the American Academy of Dermatology recommends seeking shade during peak sunlight hours, wearing protective clothing and applying a broad-spectrum sunscreen with an SPF of at least 30. Reapply every two hours – and after swimming or sweating. 

And even if you have already been caught out, it is never too late to start protecting your skin.