Not Really a Worm At All
Ringworm, technically called dermatophytosis or dermatomycosis, is a skin condition that can be transmitted between people and pets. It is caused by one of several kinds of microscopic fungal organisms. The disease gets its confusing name from the fact that a common symptom in people is the appearance of a reddish ring on the skin which was once thought to be cause by a worm.
Ringworm in Pets
Ringworm fungi can infect dogs, cats, rabbits, farm animals, and other mammals. Pets with ringworm often have areas of hair loss. The skin in these areas may become crusty or scaly, and the hair breaks off easily. The lesions increase in size quickly and can spread over the entire body. However, some infected animals, especially cats, do not show any symptoms at all.
Ringworm is diagnosed by the appearance of the lesions, plus the results of one or more tests. Some types of ringworm will glow under ultraviolet light. Hairs or a skin scraping from the affected area can be examined under the microscope to look for the fungal organisms. The most sensitive test is culturing; hairs are applied to a growth media and observed for development of the ringworm fungus.
Mild cases of ringworm can be treated with topical antifungal creams. Sometimes it is beneficial to shave the affected area prior to application of the medication. Antifungal shampoos and dips are also available. In more severe cases, hair is shaved from the entire body of the pet and repeated shampoos or dips are performed. Oral medication may also be prescribed in these more serious cases. A ringworm vaccine is available for cats but is not helpful in all cases your veterinarian can advise you whether it would be of benefit.
Ringworm in People
A telltale ring-like marking on the skin is the most common sign of ringworm in people. Lesions can be seen on the skin or on the scalp. In people, the disease is also called tinea. Most people recover quickly from this condition, especially with treatment.
Ringworm in people is mainly diagnosed by the appearance of the lesions, but a skin scraping may be performed to confirm the disease.
Most human cases of ringworm are treated with a simple antifungal cream applied to the lesion. Keeping the skin clean and dry is also helpful. Because people are not as hairy as pets, the condition is more easily treated in humans, and most people recover within a few weeks. People who are properly applying antifungal medication are generally not considered contagious during treatment. Unless your doctor advises otherwise, it is usually OK to go to school or work.
Preventing the Spread of Ringworm
Ringworm is highly contagious. The fungus produces spores on the skin or hair these tiny spores can fall off and survive in the environment for long periods of time. People and pets may be exposed to the spores by contact with other people, pets, or soil. Ringworm can be spread by objects such as brushes, combs, unwashed clothing, and in showers and pools.
People most commonly get ringworm from other people. Avoid sharing brushes, combs, or clothing. Wear sandals when using public showers. Keep your skin and hair clean and dry.
Animals can also be an important source of infection. Avoid handling stray animals showing signs of ringworm. Pets with signs of ringworm should be seen by the veterinarian, tested, and treated. During treatment, minimize handling of the animal and keep it separate from other pets. Infected pets can be contagious even after the obvious symptoms have resolved, so it is important to use medications for the full duration prescribed and see your veterinarian for follow-up testing. Some animals, most commonly cats, can be carriers of ringworm without showing symptoms. If you become infected with ringworm and the source of infection is unknown, your doctor may recommend having your pets tested