Ringworm Dr Trisha Macnair Ringworm is the common name for a group of fungal infections of the skin, hair and nails.

In this article

What's the cause? Who's affected?

What are the symptoms? How's it diagnosed?

What's the treatment?

Despite the name, ringworm has nothing to do with worms. The proper medical name for these infections is tinea, often followed by the Latin name for the affected part of the body. For example, tinea pedis affects the feet (and is better known as athlete's foot), tinea corporis affects the body and tinea capitis affects the scalp.

Ringworm is caused by fungal infection, mostly by a group of fungi called dermatophytes. Spores of the fungus may be picked up from another person, the soil, a domestic animal or household objects.

Anyone can develop ringworm but it's more likely to happen when there's a local breakdown of the immune defences, such as a scratch in the skin, which allows the fungal spores to invade.

In athlete's foot, for example, sweaty conditions between the toes make the skin too moist to act as a proper barrier to micro-organisms.

Ringworm usually causes reddened and scaly patches on the skin, which form in an irregular ring shape with a slightly raised edge. The patches may be very itchy. In tinea capitis, the hair inside the patches may be lost, resulting circular bald areas.

Ringworm can also affect the nails, causing them to become thickened and discoloured, with scaling of the palms or soles.

Ringworm can usually be identified on the basis of its appearance. The diagnosis is confirmed by examining scrapings of the skin in the laboratory to look for the fungus.

Some types of ringworm fungi fluoresce under ultraviolet light, but this test isn't conclusive because many don't.

Ringworm is usually easily treated with antifungal creams and lotions. These may need to be applied for several weeks to be fully effective and prevent recurrence because the fungi can be buried deep in the skin tissues.

Occasionally, especially in widespread infections or those involving the nails or hair, antifungal treatment is given in tablet form over many weeks. In fact, occasionally treatment is needed for as long as two years. Always go back to your doctor if the problem recurs.

This article was last medically reviewed by Dr Orlena Kerek in March 2009