Ringworm

From Wikipedia, the free encyclopedia

Ringworm
Classifications and external resources
ICD-10 B35-B36
ICD-9 110.9

Ringworm, also known as Tinea, is a contagious (excluding tinea versicolor[1]) fungal infection of the skin. Contrary to its name, ringworm is not caused by a worm.

Ringworm is very common, especially among children, and may be spread by skin-to-skin contact, as well as via contact with contaminated items such as hairbrushes. Ringworm spreads readily, as those infected are contagious even before they show symptoms of the disease. Participants in contact sports such as wrestling have a risk of contracting the fungal infection through skin-to-skin contact.

Tinea capitis
Enlarge
Tinea capitis

Ringworm is also a common infection in domestic animals, especially cattle and cats. Humans can contract ringworm from animals; cats, cattle and dogs are common sources owing to close association with humans.

Contents

[edit] Types

A number of species of fungi cause ringworm. Dermatophytes of the genera Trichophyton and Microsporum are the most common causative agents. These fungi attack various parts of the body and lead to the following conditions:

[edit] Symptoms and diagnosis

The best known sign of ringworm in people is the appearance of one or more red raised itchy patches with defined edges, not unlike the herald rash of Pityriasis rosea. These patches are often lighter in the center, taking on the appearance of a ring. If the infected area involves the scalp or beard area, then bald patches may become evident. The affected area may become itchy for periods of time. If the nails are affected, they may thicken, discolor, and finally crumble and fall off.

Plucked hair treated with KOH showing ectothrix spores and hyphae from a case of feline ringworm
Enlarge
Plucked hair treated with KOH showing ectothrix spores and hyphae from a case of feline ringworm

Doctors can diagnose ringworm on sight, or they may take a skin scraping, or in the case of animal ringworm or tinea capitis, examine plucked hairs for fungal elements. This is examined under a microscope, or put on an agar plate in a microbiology laboratory and allowed to grow.

Specialized agar plate, called Dermatophyte Test Medium is used to culture and identify ringworm organisms
Enlarge
Specialized agar plate, called Dermatophyte Test Medium is used to culture and identify ringworm organisms

Some of the fungi fluoresce under a black light examination.

In domestic animals, ringworm can cause a variety of symptoms, but most cases show scaling and patches of hair loss. Some cats can be carriers, but show no symptoms.

[edit] Treatment

Topical antifungal drugs containing miconazole and clotrimazole, available by prescription or over the counter, are used to clear up the infection. A folk remedy for ringworm is a 1:1 solution of cider vinegar and water. Another alternative is 2 drops tea tree oil mixed with an ounce of water. In cats and cattle, sulfurated lime rinses are often used to treat ringworm. Enilconazole, as a rinse, is an effective ringworm treatment available in many countries for treating animals. Fungal infections may take a while to clear up.

Terbinafine is highly effective for Tinea corporis. It treats itching, burning, cracking, and scaling that accompany this condition. It cures most ringworm except the types affecting the nails or scalp, which are very difficult to treat.

Griseofulvin is a traditional drug used to treat ringworm in both animals and man. It can be very effective, but may produce side effects.

[edit] See also

[edit] References

  1. ^ [1] URI last accessed 11 May 2006.