There are some itches you can deal with immediately. An itchy arm? Scratch it. An itchy scalp? No problem. An itchy groin that suddenly announces itself halfway through a work meeting, on the school run or standing in the supermarket queue? That requires considerably more self-control.

And when the itching keeps coming back, particularly if you have noticed a rash spreading across the groin or inner thighs, one possible culprit is jock itch.

Despite the name, you do not need to be a jock, own a pair of football boots or have stepped inside a gym recently to get it.

Jock itch, medically known as Tinea cruris, is a common fungal skin infection affecting the groin, inner thighs and sometimes the buttocks.

It is more common in men, partly because of the anatomy of the groin, but women can get it too.

Like most fungi, the organisms responsible are fond of warm, moist environments. Unfortunately, a combination of underwear, sweat, skin folds and friction can provide exactly that.

Add a hot day, a workout or a few hours sitting around in damp gym clothes and you have created rather comfortable living conditions for an unwanted guest.

How would you know if it’s jock itch?

Jock itch typically causes an itchy, scaly rash around the groin and upper inner thighs. It may have a more obvious raised or defined edge and can spread outwards, sometimes creating a curved or ring-like shape.

And remember that rashes do not look the same on every skin tone.

On lighter skin, the affected inflamed area may look pink or red. On brown or black skin, it may be darker brown, purple, grey or simply noticeably different from the surrounding skin.

The itching can be intense and heat, exercise and sweating may make symptoms considerably worse. People who exercise frequently can be more susceptible, particularly if they stay in their sweaty workout clothes afterwards because this creates an environment where fungi thrive.

And if you have diabetes or a weakened immune system, you may be more susceptible to these fungal infections.

The infection is caused by a group of fungi called dermatophytes. These can be picked up from another infected area of your own body, another person, contaminated objects such as towels and clothing – and even from infected animals. Once they reach the right environment, they infect the outermost layer of the skin.

In fact, these are the same types of fungi responsible for athlete’s foot – so if you already have athlete’s foot, the fungus can be transferred from your feet to your groin (via hands, towels or clothing – even as you pull underwear over infected feet).

That’s important to remember: if you have an itchy groin alongside peeling, cracked or itchy skin between your toes, do not concentrate solely on what is happening right below the waist. Your feet may need treating, too.

The fungi responsible for jock itch can spread through close skin-to-skin contact, too.

Infected skin can shed microscopic fungal material, including spores, which can contaminate these objects such as towels and help spread the infection.

Jock itch is not a sexually transmitted infection (STI) – but there is also no obvious sign that can reliably distinguish an STI from a fungal infection.

But while a fungal infection would present as an itchy, scaly rash with a relatively well-defined edge, if a patient also had genital sores, blisters or ulcers, unusual discharge, pain when passing urine or pelvic pain, I’d consider other causes, including an STI (which can be identified with testing).

So how do you actually get rid of jock itch?

First, be mindful: while you have an active fungal infection, avoid sharing towels and wash underwear, towels, bedding and clothing regularly to avoid it spreading to others.

The good news is that most cases can be treated with an antifungal medicine available over-the-counter from a pharmacy.

Common treatments include antifungal creams containing clotrimazole or terbinafine, which essentially interfere with the fungus’ cell membrane, stopping it growing.

One of the easiest mistakes to make is stopping treatment the moment the itching disappears.

Your skin feeling better does not necessarily mean the infection has completely cleared. Depending on the product, treatment may range from around one week to several weeks – and it’s important to complete the recommended course, even if things are looking considerably happier down there.

You also want to make the area much less appealing for fungi.

That means keeping the groin clean and dry, particularly after exercise or sweating; changing out of damp gym clothes as soon as possible; changing your underwear daily – and opting for loose-fitting, breathable clothing if you are prone to fungal infections.

If you also have athlete’s foot, treat that at the same time. Many of the same topical antifungals can be used for both (check with a pharmacist if you’re unsure).

Hot wash towels and underwear frequently, where the fabric allows it – regular laundering, thoroughly drying your clothes and towels and not sharing them while you have an active infection are the important bits.

And resist the temptation to rummage through the bathroom cabinet and apply whichever cream happens to be closest.

Steroid creams, which are commonly used to reduce inflammation in conditions such as eczema, can reduce redness and itching – this might give the impression that the problem is improving, but using a steroid alone on a fungal infection can alter its appearance and potentially allow it to spread, making it more difficult to recognise and treat.

The rash can become less scaly, lose its characteristic raised border and become more extensive. It may even develop pustules.

Doctors sometimes call this a steroid-modified fungal infection, or tinea incognito.

In certain circumstances a clinician may recommend a short course of a mild steroid alongside an antifungal – but the point is, do not self-treat an undiagnosed groin rash with steroid cream alone.

Another important point is that not every itchy groin is jock itch.

Eczema, psoriasis, irritation from soaps or other products, heat, sweating and friction can all cause rashes around the groin.

The yeast Candida can cause soreness and irritation too.

There can be considerable overlap, which is exactly why persistent or unusual rashes deserve a proper look.

A doctor can often diagnose the problem from its appearance and your history. If there is doubt, skin scrapings can be taken to look for fungus.

I would also want to know about a presumed fungal infection that keeps returning or simply refuses to clear despite appropriate treatment.

Also seek medical advice if the rash is severe, painful, blistering, weeping or rapidly spreading, if you develop sores or unusual genital symptoms, or if you are worried you may have been exposed to an STI.

If you have a compromised immune system or diabetes it is sensible to have a lower threshold for seeking medical advice about persistent or recurrent skin infections. Higher blood glucose levels can make certain infections more likely, while diabetes can also affect aspects of the body’s immune response.

Similarly, people whose immune systems are suppressed by an illness or medication may occasionally require different treatment, so it is worth getting medical advice rather than repeatedly treating the problem yourself.

Most cases of jock itch are very treatable. The key is recognising what you might be dealing with, treating it properly and removing some of the warm, damp conditions that allow fungus to flourish.

And if you are still not sure what is causing that persistent itch, get it checked.

Because while scratching might provide a few seconds of satisfaction, finding out what is actually causing it will give you considerably longer relief.