Phoebe MacDonald, age 14, of Lake Charles, La., for her question:

WHAT CAUSES A FUNGUS INFECTION?

A fungus infection is a disease that is caused by the growth of fungi either on the body or in it. Usually a fungal infection in a healthy person is mild and only involves the skin, hair or nails.

Familiar fungus infections are ringworm and athlete's foot.

Fungi can sometimes invade internal organs of the body. The lungs are often the target of infections resulting in pneumonia or pulmonary tuberculosis. Fungi strikes in this fashion sometimes if a person's immune system has been slowed down by anti cancer drugs or by radiation.

Doctors have many drugs available for treating fungal infections. Some are given orally and others are injected intravenously.

Doctors now have long term therapy for fungus infection with an oral drug.