5 skin symptoms that can signal an underlying health problem.

Image: iStock.

If your skin could talk, it would probably have a lot to say to you. “You forgot to wear sunscreen again?”, for instance. Or, “Seriously, lady, quit squeezing that damn pimple”.

Just because your skin can’t communicate verbally, doesn’t mean it’s not capable of letting you know when something’s wrong. Many common skin issues can signal underlying health problems — potentially serious ones — you mightn’t be aware of.

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Here are five of them.

1. Acne

Acne is an extremely common skin condition that affects 85 per cent of Australians aged between 15 and 24. Generally acne is the result of hormonal changes or a family history of the condition but certain presentations can point to other causes, explains Dr Li-Chuen Wong, a consultant dermatologist aligned with Aveeno and Newtown's Sydney Skin.

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"A female who starts to get acne around the jaw, we call it 'muzzle acne', and breakouts particularly before having periods — and it's hard for them as well to lose weight and they have hair on the upper lip — might have  polycystic ovarian syndrome (PCOS)," Dr Wong says.

"If you get acne and it's monomorphic, so all the lesions look exactly the same and they're on the upper back and chest, you have to wonder whether the patient is having annabolic steroids." (Post continues after gallery.)

2. Discolouration

If you've ever noticed your skin looking a different colour to usual, especially in concentrated areas of your face and body, it could be a sign there's something else going on below the surface.

"If you start to look yellow — a yellow skin discolouration and the whites of your eyes start going yellow as well — you need to look into whether you have any liver problems," explains Dr Wong.

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Dr Wong says discolouration is sometimes accompanied by a raised effect on the skin, which tends to indicate very specific health issues.

"If there's a dark discolouration and it's raised and feels a bit velvety on the back of your legs, your neck and in your armpits, that's called Acanthosis nigricans. That can be a sign of insulin resistance, so if you're overweight or obese you might have PCOS and insulin resistance, and it's a marker for diabetes," she explains.

High cholesterol is another condition that can present on the skin. "When you get yellow patches or 'plaques' in the corners of your eyes, on your upper eyelids, they're called xanthelasmas — that's a sign you should get your cholesterol checked," Dr Wong says. If these plaques present around your elbows and knees, your cholesterol levels could be dangerously high.

3. Dark circles

If you've had a massive weekend and spent a little less time in bed than usual, you can probably expect a bit of darkness under your eyes. But this common colour change isn't always tied to fatigue.

"In kids and adults who get those really dark circles around the eyes, and scaliness, that's a sign of house dust mite allergy," Dr Wong says. Anemia and allergies can also contribute to this discolouration.

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4. Rashes

Unsurprisingly, rashes often act as a red flag for viral infections or health conditions.

"A really acute red rash, with sudden onset of a runny nose, fever and joint aches and pains can mean you have an underlying viral infection," Dr Wong says. "Often viruses will cause what we call a viral exanthem, a viral rash. A classic example is measles or rubella, which can present with red rashes as well as other symptoms. Generally that will resolve within 10 to 14 days."

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Some viral rashes are more urgent, however. The life-threatening meningococcal disease presents as red spots on the skin that don't "blanche" when you press down on them. It requires immediate medical attention.

The autoimmune condition lupus is also associated with a specific kind of rash, called a "butterfly rash". "You typically get a rash in the sun-exposed areas on the face, the back of the hands, the arms ... typically it's the shape of a butterfly and it's on your cheeks and your nose. You also feel quite ill and have aches and pains," Dr Wong explains.

5. Eczema

Eczema flare-ups can result from a number of environmental factors, including the weather. But Dr Wong says they can also signal a compromised immune system. "[Those factors] can include being sick — so your immune system's depressed — or stress, because it does impact on your immune system," she says.

The itching caused by eczema's characteristic patches of scaley skin is also known to disturb sleep, which can then affect health more generally.

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If you're concerned by any skin symptoms you've noticed, Dr Wong recommends making an appointment with a dermatologist within a week or two, unless you're feeling unwell in general.

"I think GPs are good with really common skin problems, but if you're worried that a rash has persisted and you're feeling not great as well, I'd see a dermatologist. They can do a skin biopsy and appropriate blood tests," she says.

Have you ever experienced one of these symptoms?