Ringworm

Ringworm is a common and highly infectious skin infection that causes a ring-like red rash on the skin.

Introduction

Ringworm is a common and highly infectious skin infection that causes a ring-like red rash on the skin.

The rash can appear almost anywhere on the body, with the scalp, feet and groin being common sites.

The condition, medically known as "tinea", isn't serious and is usually easily treated using creams sold by the pharmacy. However, ringworm is highly contagious and easily spread among people.

Despite its name, it doesn't have anything to do with worms. It's an infection of the skin caused by a fungus.

When to see a doctor

You need to see your doctor if you or your child have ringworm of the scalp. This type of ringworm is treated with antifungal tablets only available on prescription.

Other types of ringworm are generally treated with antifungal cream from the pharmacy and you don't need to see a doctor unless the infection persists. However, pharmacists often prefer children to see a doctor to confirm a diagnosis.

Read more about ringworm symptoms.

How do you get ringworm?

Ringworm is passed between people through direct skin contact and by sharing objects such as towels, hairbrushes and bedding.

Pets such as dogs and cats can have ringworm, which they can pass on to people they come into contact with.

Read more about the causes of ringworm.

Who is affected?

Ringworm is common. It's estimated that 10-20% of people will have a fungal skin infection at some point during their lifetime.

People of all ages can be affected by ringworm, but children are particularly susceptible to it.

Scalp ringworm (tinea capitis) is most common in children who have not reached puberty (sexual maturity), particularly African-Caribbean children and those who live in urban areas.

Body ringworm can affect anyone of any age, although groin infections are more common in young men.

Treating ringworm

Most cases of ringworm are mild and can be treated using a pharmacy antifungal cream.

Scalp ringworm can be treated with antifungal tablets, sometimes combined with antifungal shampoo.

Sometimes, if ringworm leaves the skin irritated or broken it can lead to other bacterial infections, which may need treatment with antibiotics.

Read more about how to treat ringworm.

Stopping it spreading

It's really important, where possible, to prevent spreading the infection. You should avoid sharing towels, bedding or clothes with anyone diagnosed with ringworm.

If you think your pet has ringworm, take it to the vet. If your pet is treated quickly, you will be less likely to catch the infection from it.

If your child has ringworm, they do not need to stay off school. However, you should inform the school your child has the condition. In addition to treatment, your child should maintain a good level of personal hygiene to prevent the infection spreading.

Read more about how to stop the spread of ringworm.

Symptoms

Ringworm often looks like a round, red or silvery patch of skin that may be scaly and itchy.

The ring spreads outwards as it progresses. You can have one patch or several patches of ringworm, and in more serious cases your skin may become raised and blistered.

Scalp ringworm

The symptoms of scalp ringworm include:

  • small patches of scaly skin on the scalp, which may be sore
  • patchy hair loss
  • an itchy scalp

In more severe cases, symptoms can also include:

  • small, pus-filled sores on the scalp
  • crusting on the scalp

In very severe cases of scalp ringworm, a large inflamed sore called a kerion may form on your scalp. This can ooze pus, and you may also have a fever and swollen lymph glands.

Body ringworm

The symptoms of body ringworm include:

  • a ring-like red rash on your skin – your skin will look red and irritated around the ring but healthy inside

In more severe cases:

  • the rings may multiply, grow in size and merge together
  • the rings may feel slightly raised to the touch and the skin under the rash may be itchy
  • blisters and pus-filled sores may form around the rings

Foot ringworm (athlete's foot)

The symptoms of foot ringworm (athlete's foot) include:

  • an itchy, dry, red and flaky rash, usually in the spaces between your toes

And, in more severe cases:

  • cracked skin in the affected area
  • blisters, which may ooze or crust
  • swelling of the skin
  • a burning or stinging sensation in your skin
  • scaling patterns around your sole and on the side of your foot

Read more about athlete's foot.

Groin ringworm (jock itch)

The symptoms of groin ringworm (jock itch) include:

  • red-brown sores (not necessarily ring-shaped), which may have blisters or pus-filled sores around the edge
  • itchiness and redness around your groin area, such as your inner thighs and bottom (the genitals are not usually affected)
  • the skin on your inner thighs can become scaly and flaky

Exercising, walking and wearing tight clothing or underwear can make the symptoms of a groin infection worse.

It's also quite common to develop a groin infection in combination with athlete's foot. This can happen if you have athlete's foot and you scratch your foot and transfer fungal spores to your groin when dressing or going to the toilet.

Ringworm of the nails (fungal nail)

The symptoms of nail ringworm include:

  • a whitish thickening of the nail
  • discolouration (the nail can turn white, black, yellow or green)
  • the nail can become brittle and start to fall off
  • the skin around the nail may be sore and irritated

Read more about fungal nail infection.

Read more about how ringworm is diagnosed.

Causes

Ringworm is a skin infection caused by a fungus.

Ringworm is caused by fungi called dermatophytes, which live off keratin. Keratin is a tough, waterproof tissue found in many parts of the body, including the skin, nails and hair.

This is why ringworm infections mostly affect the skin, nails or scalp.

How ringworm spreads

The fungi are tiny spores tough enough to survive for months on your skin, in soil or on household objects, such as combs or towels. The spores can be spread in four different ways:

  • human-to-human contact
  • human-to-animal contact – for example, by stroking an infected dog or cat
  • human-to-object contact – both animals and humans can leave traces of fungi spores on objects and surfaces, such as towels, clothing, bed linen, combs or brushes
  • human-to-soil contact – less commonly, you can develop a ringworm infection after lengthy exposure to infected soil

As an adult, you can become a carrier of scalp ringworm without developing any symptoms. This is because your body has usually developed a defence against the infection by the time you reach adulthood.

If you are a carrier of a ringworm infection, you can unknowingly pass the condition onto children, who may then go on to develop symptoms.

Risk groups

You are more likely to develop ringworm if you:

  • are very young or very old
  • are African-Caribbean (in the case of scalp ringworm)
  • have type 1 diabetes
  • are very overweight (obese)
  • have a medical condition that weakens your immune system, such as HIV or AIDS
  • are receiving medical treatment that weakens your immune system, such as chemotherapy or steroid tablets
  • have had fungal infections in the past
  • have hardening of your arteries (atherosclerosis)
  • have poor circulation (specifically a condition called venous insufficiency, where the veins in your legs have trouble moving blood back to your heart)

Diagnosis

Ringworm is usually easy to diagnose from its appearance and location.

Scalp ringworm

Your doctor will usually be able to diagnose scalp ringworm after examining your scalp.

Knowing what type of fungus is causing the ringworm infection can be useful, as some types of antifungal medication are better at treating certain types of fungi. Your doctor will remove a small sample of skin from your scalp for testing in a laboratory.

You may be given an antifungal medication to start taking before you receive your test results. If the tests show a different antifungal medication would work better, you will be prescribed that and asked to stop taking the first one.

Body ringworm

Most cases of body ringworm can be diagnosed by your doctor after examining your skin and asking you whether you have other symptoms that could be related.

Further tests will usually only be needed if your symptoms are severe or if they fail to respond to antifungal treatment. If this is the case, your doctor may remove a small piece of affected skin and send it to a laboratory to be analysed under a microscope.

Microscopic analysis will be able to show if fungi are present and the specific type causing your infection.

Read about how to treat ringworm.

Treatment

Ringworm is easily treated using antifungal creams, tablets and shampoo.

The following self-help tips can also help get rid of ringworm and stop it from spreading:

  • wash areas of skin affected by ringworm daily and dry thoroughly, paying particular attention to skin folds and the areas between your toes
  • in the case of a groin or foot infection, change your underwear or socks daily as fungi can persist in flakes of skin
  • in the case of scalp infection, do not share combs, hairbrushes or hats
  • wash clothes, towels and bed linen frequently
  • wear loose-fitting clothes, preferably made of cotton or other natural materials

Read more about preventing ringworm.

Scalp ringworm

Scalp ringworm is usually treated using antifungal tablets, often in combination with an antifungal shampoo.

There are two main types of antifungal tablet:

  • terbinafine
  • griseofulvin

The antifungal medicine your doctor prescribes will depend on the type of fungi causing the infection.

Terbinafine tablets

Most people with scalp ringworm are prescribed terbinafine. It's an effective treatment for most cases of ringworm. You usually need to take the tablets once a day for four weeks.

Side effects of terbinafine can include:

These side effects are usually mild and short-lived. Some people have also reported that terbinafine temporarily affected their sense of taste.

Terbinafine is not suitable for people with a history of liver disease or lupus (where the immune system attacks healthy tissue).

Griseofulvin

Griseofulvin is a type of antifungal medicine that works by preventing fungi from growing and multiplying. It is available in the form of a spray and is usually taken daily for between 8 and 10 weeks.

Side effects of griseofulvin can include:

However, these side effects should improve as your body gets used to the medicine.

Griseofulvin can cause birth defects so shouldn't be taken during pregnancy or if you intend to become pregnant soon after stopping treatment. Men shouldn't father a child within six months of stopping treatment.

Griseofulvin is also not suitable for women who are breastfeeding and those with severe liver disease or lupus.

Griseofulvin can interfere with both the combined contraceptive pill and the progestogen-only pill, so women need to use an alternative barrier form of contraception, such as a condom, while taking it.

Griseofulvin may also affect your ability to drive and can enhance the effects of alcohol.

Read more about griseofulvin.

Antifungal shampoo

Antifungal shampoo cannot cure scalp ringworm, but it can help prevent infection spreading and may speed up recovery.

Antifungal shampoos such as selenium sulphide is available from your pharmacist. Ideally, antifungal shampoo should be used twice a week during the first two weeks of treatment.

There is no evidence that shaving a child's head will reduce the risk of a ringworm infection or speed up recovery.

Body ringworm

Most cases of body ringworm (including groin infections) can be treated using an over-the-counter antifungal cream, gel or spray. There are lots of different types, so ask your pharmacist to help choose the right one for you.

You usually apply antifungal creams, gels and sprays daily to the affected areas of skin for two weeks. The cream, gel or spray should be applied over the rash and to one inch of skin beyond the edge of the rash. Read the manufacturer's instructions first.

You may be advised to use the treatment for a further two weeks to reduce the risk of re-infection. See your doctor if your symptoms have not improved after two weeks of treatment as you may need antifungal tablets.

Both terbinafine and griseofulvin tablets can be used to treat body ringworm infections, as well as another antifungal medicine called itraconazole.

Itraconazole

Itraconazole is usually prescribed in the form of capsules for 7 or 15 days. It is not recommended for use in children, elderly people or those with severe liver disease.

Side effects of itraconazole can include:

  • nausea
  • vomiting
  • indigestion
  • diarrhoea
  • headache

Read more about [itraconazole]&medicine=Sporanox&preparation=Sporanox%20100mg%20capsules).

Read about how to stop the infection coming back.

Fungal nail infections

Fungal nail infections can be treated with antifungal nail paint or antifungal tablets. Antifungal tablets tend to work better than nail paints, although they can cause side effects such as headache, nausea and diarrhoea.

Read more about treating fungal nail infections.

Prevention

If you or someone in your family has ringworm, following the advice outlined below will help stop the infection spreading.

To contract ringworm it is not necessary to have direct contact with an infected person or animal. This is because the fungi is able to survive on items such as furniture, hairbrushes, clothing and towels.

Therefore, if someone in your household has ringworm you should:

  • avoid sharing personal items, such as combs, hairbrushes, towels, clothing and bed linen
  • wash bed linen, pillow cases and towels on a hot cycle using a normal detergent
  • wash clothing separately from bed linen, following the clothing manufacturer's instructions regarding temperature
  • wash different people's bedding and clothing separately
  • ensure every member of your household washes their hands frequently
  • ensure anyone infected with scalp ringworm uses an antifungal shampoo twice a week
  • avoid scratching the affected areas of your skin or scalp because it could spread the infection to other parts of your body

It is important other household members check themselves for signs of infection. If necessary, they should seek treatment.

If you suspect your pet is the source of the infection, take them to your vet for treatment. Patches of missing fur are a sign an animal has ringworm.

If someone in your family has ringworm, there is no need for them to stay off work or school. However, treatment should be started as soon as possible. Good personal hygiene should also be followed to stop it spreading to other children.

Find out more about how to treat ringworm.

Content supplied by NHS Choices