Ringworm

Ringworm is an outdated term for a fungal skin infection. The name ringworm -- dating back to the early 15th century -- comes from the idea that the infection was caused by a burrowing worm. There is no such thing as a ringworm.

Causes

Ringworm and other fungal skin infections such as athlete's foot and jock itch are really caused by tiny organisms that can be seen only under a microscope. Fungal infections are moderately contagious among susceptible people, and some kinds can be spread to people by cats and dogs.

Head infections:  Infections of the scalp (tinea capitis) are most commonly caused by Trichophyton tonsurans. They may occasionally be caused by Microsporum canis.

Body infections:  Infections on the body and limbs (tinea corporis) are most commonly caused by Trichophyton mentagrophytes or Tinea rubrum.

Feet:  Athlete's foot (tinea pedis) is most commonly a result of infection with Tinea mentagrophytes or Tinea rubrum.

Symptoms

Ringworm starts as a small spot, then spreads or radiates out in a ringlike pattern. It can infect most surfaces of the body, including the nails. On the scalp, it may cause itchy, red areas and hair loss. To determine if you have ringworm or another infection, your doctor can do tests by examining a piece of your nail, hair or skin under a microscope.

Self-Care

• Over-the-counter antifungal creams work well for fungal infections. Try tolnaftates (Tinactin, Aftate), clotrimazoles (Lotrimin AF, Mycelex) or miconazoles (Micatin, Monistat) on small patches, especially for areas other than the feet. Apply twice a day at least 2 centimeters past the border of the lesion for at least 2 weeks (it may take 4 to 6 weeks). Continue using for 1 week after lesion disappears.

• Keep moist areas dry. Use powder after bathing. Try drying the affected area with a hair dryer set on cool.

• Thoroughly clean combs and hats.

• Avoid sharing towels, clothing or other personal items during treatment.

• Launder all personal items frequently using hot water.

• If your pets develop scaly, hairless skin lesions, have them checked for fungal infections by a veterinarian.

Prevention

If you have a pet that develops a patch of skin where fur is missing, have the pet treated by a veterinarian. Avoid touching the animal until it has been treated and all sores or bare spots are gone. Do not share shoes with someone who has athlete's foot.