Skin accounts for around 15% of our body mass. It is the largest and most visible organ in the human body.

Yet many of the skin’s functions are often overlooked. It’s a sunscreen, a shield from germs, a reservoir of vitamin D and a means of tightly regulating our body temperature.

Being the most visible of our organs, the skin also offers us a view into the body tissues that it protects. So don’t think of your skin merely aesthetically – think of it as a reflection of your health. Disorders of the gut, blood, hormones and even the heart might first be seen on the skin in the form of a rash.

Here are a few to look out for.

Ticks are pesky creatures that no one will want to return home from a country walk with.

But while the vast majority of tick bites won’t make you ill, there is one rash that should prompt a visit to your doctor if you spot it.

Erythema migrans, a rash named for its ability to rapidly expand across the skin, is a hallmark of Lyme disease, a potentially severe bacterial illness. This rash forms a classic target pattern, like a bullseye on a dartboard.

Be vigilant for a few weeks after being bitten to check this rash doesn’t make an appearance – especially if you noticed a red lump that wasn’t........

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