Fungal, << FUHNG guhl, >> disease is any sickness caused by fungi. Fungi are simple organisms found almost everywhere in nature. Many kinds of fungi live as parasites—that is, they feed on tissues of living plants and animals, including human beings. These fungi often cause diseases in the plants and animals they infect.
In people.
The most common fungal diseases in people are skin infections, such as ringworm or athlete’s foot. These conditions can be caused by a number of fungi, including species in the groups Trichophyton, Microsporum, and Epidermophyton. Other fungi that normally live harmlessly in the body can sometimes cause disease. For example, fungi in the Candida group, which commonly inhabit the mouth, bowel, or vagina, can cause a variety of disorders, including a disease of the throat called thrush.
Many fungal diseases affect internal organs and organ systems. The most common of these systemic diseases include histoplasmosis, blastomycosis, and coccidioidomycosis. These three diseases attack the lungs and usually are not serious. However, these same disorders can occasionally be deadly in otherwise healthy people, especially those who lack natural resistance because of AIDS or other diseases. In these patients, the fungi may travel through the body to the bones, kidneys, and central nervous system. Some fungal diseases, including thrush, cryptococcosis, and histoplasmosis, are associated with AIDS and may indicate infection with the HIV virus (see AIDS).
Doctors may prescribe antifungal creams or ointments to treat fungal diseases of the skin. One of the main drugs used to treat systemic fungal diseases is amphotericin B. Fungal diseases are often cured with medication. In patients without natural resistance, however, these disorders often recur.
In animals.
Many fungal diseases of people also occur in animals, particularly mammals. Ringworm is the most common fungal disease that affects animals. Other fungal diseases that affect animals include histoplasmosis and monoliasis in mammals and aspergillosis in birds.
In plants.
Fungi that cause diseases in plants include smuts, rusts, and mildews. These fungi affect many kinds of plants and can seriously damage crops. For example, black stem rust harms wheat, covered smut attacks barley, and powdery mildew damages a wide variety of plants, such as peas and grapes. Fungal diseases that attack trees include Dutch elm disease and chestnut blight. Farmers use chemicals called fungicides to kill fungi (see Fungicide). Breeders also try to develop plants resistant to fungal attacks.
