Ringworm is a skin infection caused by a fungus. It is not caused by worms, and there are no worms involved, despite the name. Treatment with an antifungal cream usually works well.
What is ringworm?
Ringworm is a fungal skin infection. (It is not due to a worm as its name implies!) There are many types of fungal germs (fungi) and some can infect the skin, nails, and hair. Fungal infections are also known as "tinea" or "dermatophyte infections" or "dermatophytosis". This leaflet just deals with ringworm of the skin (sometimes called tinea corporis). Other leaflets deal with fungal infections of the scalp (scalp ringworm), foot (athlete's foot), groin (tinea cruris) and fungal nail infection.
How can you catch ringworm?
- From person to person by touching a person who has the infection.
- From touching items which have been in contact with an infected person. For example, towels, clothes, bed linen or chairs which have been used by somebody who has ringworm.
- From animals. Some animals such as dogs, cats, guinea pigs and cattle have fungal infections on their skin. They can pass on the infection, especially to children. (Animals can be treated too if you suspect a pet is the cause. See your vet.) Farm animals can also be a source. Touching a farm gate where infected animals pass through may be enough to infect your skin.
- From soil. Rarely, fungi can be present in soil, and you can get the infection from contact with soil.
What are the symptoms?
A small area of infected skin tends to spread outwards. It typically develops into a rounded, red, inflamed patch of skin. The outer edge is more inflamed and scaly than the paler centre. So, it often looks like a ring that becomes gradually larger - hence the name ringworm. Sometimes only one patch of infection occurs. Sometimes several patches occur over the body, particularly if you catch the infection from handling an infected animal.
The rash may be mildly irritating, but sometimes it is very itchy and inflamed. The rash may vary depending on which type of fungus causes the infection. Sometimes fungal skin infections look similar to other skin rashes, such as psoriasis.
What is the treatment?
You can buy an antifungal cream from pharmacies, or get one on prescription. There are various types and brands - for example, terbinafine, clotrimazole, econazole, ketoconazole and miconazole. These are good at clearing fungal skin infections. There is no evidence that any one cream is better than any other one.
Apply the cream for as long as advised. This varies between the different creams, so read the instructions carefully. Briefly:
- Clotrimazole: apply 2-3 times a day for at least four weeks.
- Miconazole: apply twice a day and continue for 10 days after the skin is back to normal.
- Econazole: apply twice a day until the skin is back to normal.
- Ketoconazole: apply once or twice a day and continue for a few days after the skin is back to normal. Cannot be used for children.
- Terbinafine: apply once or twice a day for one to two weeks. Cannot be used for children.
For skin that is particularly inflamed, your doctor may prescribe an antifungal cream combined with a mild steroid cream. This would normally be used for no more than seven days. You may need to continue with an antifungal cream alone for a time afterwards. The steroid reduces inflammation and may ease itch and redness quickly. However, the steroid does not kill the fungus and so a steroid cream alone should not be used.
Not all treatments are suitable for everyone. People who may not be able take antifungal tablets include:
- Women who are pregnant or breast-feeding.
- People with certain liver diseases.
- People at risk of heart failure.
- People with long-standing lung disease.
- Elderly people.
- People taking other medication which may interact with antifungal tablets.
General advice tips
Keep the affected area clean and dry.
To prevent passing on the infection, do not share towels. Wash towels, sheets and clothes frequently. Clean your shower or bath well after use. Try not to scratch the rash, as this may spread the fungus to other areas of your body.
You do not need to stay off work or school once treatment has started.
Dr Tim Kenny
Dr Mary Harding
Dr John Cox