What is ringworm (tinea corporis)?
Ringworm (tinea corporis) is a fungal infection of the skin. It causes a red or silver scaly rash, which has the appearance of rings. Despite what its name might suggest, ringworm is not caused by worms – it gets its name from its circular appearance.
It is a fairly common condition, affecting between 10 and 20% of people during their lifetime. It usually appears on the arms or legs but can affect the scalp, groin, feet and nails. It is a fungus that likes moist, warm conditions and is easily spread via contact with pets, infected surfaces or direct contact. (See Causes)
In most cases, ringworm is effectively treated with an antifungal cream or ointment (See Treatments).
The main symptom of ringworm is patches of red, inflamed skin. The patches may also develop pale or silvery scales. As the outer edges of patches tend to be more inflamed and have more scales, they tend to look like rings. Patches may also be itchy.
As the infection progresses, the rings spread outwards. In more severe cases of ringworm, several rings may develop and it possible for the rings to merge together. The rings may also be slightly raised off the surface of the skin and blisters or pustules (pus-filled lumps) can form
Ringworm usually affects the arms and legs, although anywhere on the body can be affected. Similar fungal infections (called ‘tinea’) can affect the scalp (scalp ringworm), groin (tinea cruris), feet (Athlete’s foot) and nails (onychomycosis).
Ringworm is a type of ‘tinea’ fungal infection – a group of infections caused by fungi known as dermatophytes. Dermatophytes grow and survive in keratin, a protein that is a major component of skin, hair and nails.
The spores of the fungi thrive in warm, moist conditions. In addition to the outer layer of skin, they are also capable of surviving in soil and on inanimate objects like towels or combs. As a result, there are 4 main ways in which ringworm can spread:
- human-to-human contact – touching another person who has the infection
- human-to-object contact – touching things such as towels, bed sheets and clothes which have been in contact with an infected person or otherwise contain spores.
- human-to-animal contact – touching an infected animal’s fur, e.g. stroking a dog or cat
- human-to-soil contact – prolonged contact with soil that contains fungal spores
A GP can diagnose ringworm from a simple examination of your skin. Further tests are not usually required. In some cases, a GP may take scrapings of the skin to be analysed in a laboratory.
Referral to a specialist
You may be referred to dermatologist if the GP is unsure of your diagnosis or the ringworm infection is not responding to treatment.
Most cases of ringworm are effectively treated with a topical antifungal cream or ointment. For skin that is very inflamed, you GP may additionally prescribe a topical steroid cream. In very severe cases, oral antifungal medication may be necessary to combat the infection.
Topical antifungals are creams and ointments that contain antifungal drugs that destroy the dermatophytes responsible for ringworm. Topical antifungals include: clotrimazole, econazole and miconazole. Ketoconazole and terbinafine are sometimes used, although these topical medications are not suitable for children.
Topical antifungals may cause itching, redness and/or a mild burning sensation when applied to the skin.
Topical corticosteroids are creams or ointments containing steroid drugs that dampen the immune response and reduce inflammation. 1% hydrocortisone cream is often used and applied to the skin once or twice a day, for a maximum of seven days.
Applying topical corticosteroids to the skin may cause a slight burning sensation.
If topical antifungals have not been effective or in the event of severe ringworm, a GP may describe oral antifungal tablets. The antifungal drugs enter the bloodstream and work to destroy the dermatophytes on the skin. Oral antifungals for the treatment of ringworm include: terbinafine, griseofluvin and itraconazole. These drugs may cause nausea, abdominal pain and headaches as side effects.
Wash affected areas of skin regularly
Washing affecting areas of skin and drying them thoroughly everday can help soothe symptoms and prevent spread of ringworm. It is particularly important to wash and dry skinfolds, as these can often harbour fungal spores.
Wash clothes and bed line regularly
Fungal spores can survive in clothes and bed linen and spread to humans. Washing these regularly can help reduce the chance of getting and spreading ringworm.
Avoid sharing towels
Fungal spores can thrive on the moisture in towels and be spread from person to person. It is advised to not share towels and to wash towels regularly.
Consider wearing loose fitting clothing
Loose fitting clothing can help prevent moisture from developing on the skin and fungal spores from thriving. Natural fibres such as cotton or wool that allow the skin to breathe may also be helpful.
NHS Choices. Ringworm and other fungal infections. Available online at: http://www.nhs.uk/Conditions/Ringworm/Pages/Introduction.aspx
NICE CKS. Fungal skin infection – body and groin. Available online at: https://cks.nice.org.uk/fungal-skin-infection-body-and-groin
Patient.info. Ringworm (tinea corporis). Available online at: http://patient.info/health/ringworm-tinea-corporis
Patient.info. Dermatophytosis (tinea infections). Available online at: http://patient.info/doctor/dermatophytosis-tinea-infections