Ringworm on the body: symptoms and treatment

Ringworm is the everyday name for a skin infection caused by fungi. The medical term for the form that affects the trunk, arms and legs is tinea corporis, but most people simply hear "ringworm". The name comes from the ring-shaped appearance of the rash, and from an old belief that a worm lay under the skin. No worm is involved.

The fungi responsible are called dermatophytes. The British Association of Dermatologists describes them as organisms found in humans, animals and the environment, with Trichophyton and Microsporum among the common species. They feed on keratin, the protein in the outer skin layer, hair and nails, which is why the infection stays on the surface rather than going deeper into the body.

The same family of fungi causes athlete's foot, groin infections, scalp infections and fungal nail infections. The NHS lists nails and feet as separate common fungal infections, and notes that ringworm can appear anywhere on the body, including the scalp and groin.

NHS inform describes a red or silvery ring-like rash, with skin that looks red and irritated around the ring and healthy inside. You may have one patch or several, and the rash can spread outwards. The skin can also be scaly, itchy or inflamed. In more serious cases, NHS inform says the skin may become raised and blistered.

It most often affects the arms and legs, although it can appear almost anywhere. On darker skin the NHS notes that colour change may be less obvious, so the shape, scaling and itch are often more helpful clues than redness alone.

• Face and neck: the rash may not look like a ring at all. It may be itchy, swollen, dry and crusted, and in a beard the hair can break away in patches.

• Hands: the skin on the palm and between the fingers often becomes thicker. It may affect one or both hands but normally shows on one side.

• Several patches: one rash can spread, or more than one rash can appear, which is one reason to start treatment early.

• Scratching: the NHS advises against scratching, because it could spread the infection to other parts of the body.

Anyone can get ringworm, but NHS inform says children are more likely to be affected. The fungus passes on through close contact with an infected person or animal, or through objects such as clothing, towels, combs and bedsheets. Infected soil can also be a source, though the NHS says this is less common.

Pets are a frequent link. Patches of missing fur on a cat or dog are a reason to see a vet, and both NHS pages suggest checking your own skin if you have been in contact with an infected person or animal. Washing hands after touching animals or soil is part of the standard advice.

The fungus can survive on surfaces. The British Association of Dermatologists notes, in its scalp leaflet, that dermatophytes can live for long periods in the environment, so an infection can show up many months after exposure. That helps explain why a household can seem to pass a rash back and forth.

Both NHS sources describe ringworm as usually mild and treatable with antifungal medicine bought from a pharmacy. The form depends on the location: tablets, cream, gel or spray. A pharmacist can examine the rash, suggest a product and tell you whether a GP visit makes sense. This is a practical route because most people do not need a prescription.

The NHS says you may need to use the antifungal every day for up to 4 weeks. It specifically warns that finishing the full course matters even if the rash looks gone,.

If the skin is irritated or broken, NHS inform notes it can become infected with bacteria, and that may need antibiotics. That is a reason to get a GP to look at a rash that looks angry, weeping or increasingly painful rather than simply itchy.

The NHS lists three situations: the rash has not improved after the antifungal your pharmacist recommended, the ringworm is on the scalp, or you have a weakened immune system. In the scalp case you will usually need prescription antifungal tablets and shampoo. Chemotherapy, steroid treatment and diabetes are the examples the NHS gives for reduced immunity.

At the appointment, a GP will examine the skin and ask about your symptoms. NHS inform says further tests are usually only needed if symptoms are severe or do not respond to antifungal treatment. In that case the GP may take a small scraping of skin to be analysed in a laboratory to identify the cause.

If treatment has failed, the next step is usually a different antifungal, sometimes as tablets. A persistent rash that is not ringworm at all, such as eczema or psoriasis, would need a different approach, which is why a lab result can be useful.

Treatment started early is the single most useful step. Beyond that, the NHS advice is practical. Wash towels and bedsheets regularly, keep skin clean, wash your hands after touching animals or soil, and check your skin if you have had contact with someone who has ringworm. Do not share towels, combs or bedsheets with an affected person.

Children can usually carry on at school or nursery. The NHS says it is fine for a child to attend once treatment has started, and suggests letting their teachers know. For adults, NHS inform says a family member with a fungal infection can go to work or school.

Pets should be checked too. A vet can confirm and treat animal ringworm, which prevents the infection returning to the household after your own rash clears.

In practice, most ringworm is handled entirely within community pharmacy and general practice, so a hospital dermatology appointment is rarely needed. A referral becomes more likely if the diagnosis is unclear, a rash has not cleared after more than one treatment, or the person has another condition that affects the skin or immune system.

Where the rash is hard to tell from other conditions, a dermatologist may use a skin scraping, a technique the NHS describes at GP level too. Private dermatology appointments follow the same diagnostic logic. The treatments themselves are the same antifungal medicines whichever route you use.