Fungal Infections Health Article

Definition

Fungi are types of parasitic plants that include molds, mildew, and yeast. A fungal infection is an inflammatory condition in which fungi multiply and invade the skin, the digestive tract, the genitals, and other body tissues, particularly, the lungs and liver. Fungal infections of the skin are often called ringworm or tinea.

Description

Microscopic fungi, which are called dermatophytes, often live exclusively on such dead body tissues as hair, the outer layer of the skin, and the nails. The fungus grows best in moist, damp, dark places with poor ventilation and on skin that is irritated, weakened, or continuously moist. Superficial fungal infections include tinea capitis, an infection of the neck and scalp; tinea barbae, also called barber's itch, along the beard area in adult males; tinea corporis on parts of the body, such as the arms, shoulders, or face; tinea cruris, or jock itch, involving the groin; tinea pedis, or athlete's foot; tinea versicolor; and tinea unguium, or infection of the nails. The term tinea gladiatorum is sometimes used to describe ringworm infections in atheletes. Tinea gladiatorum is most common in swimmers, wrestlers, and athletes involved in other contact sports. Fungal infections of the skin and nails are very common in children, but they can affect all age groups.

Systemic fungal infections occur when spores are touched or inhaled, or there is an overgrowth of fungi in or on the body. Such infections are most often a serious problem in those with suppressed immune systems. Candidiasis is a rather common fungal infection. When it occurs in the mouth, it is called thrush. Less often, it occurs in the mucous membranes of other parts of the digestive system, or in the vagina, heart valves, urinary tract, eyes, or blood. Other systemic fungal infections include aspergillosis, which mostly affects the lungs and may also spread to the brain and kidneys; blastomycosis, a lung infection that may spread through the bloodstream; coccidioidomycosis, also known as San Joaquin or valley fever; mucormycosis, which can develop into a very serious, life-threatening infection; and histoplasmosis.

Causes & symptoms

Fungi are widespread in the environment, so it is not unusual that a certain amount of fungi and their spores end up being inhaled into the lungs or landing on the skin. Under conditions of moisture, warmth, irritation, or injury, these fungi grow rapidly and may cause illness. Superficial fungal infections may be due to an overgrowth of fungi already present, or the infection may be the result of contact with an infected person or with contaminated surfaces, bed sheets, towels, or clothing. Fungal infections can be spread from one part of the body to another by scratching or touching. Additionally, tinea unguium infections

have been linked to the use of methyl methacrylate, a glue used for attaching acrylic fingernails.

Fungal spores are often present in soil and are likely to be inhaled when the soil is dug up or otherwise disturbed. Systemic fungal infections are commonly contracted in this way. In addition, fungi that normally inhabit the intestines, such as Candida albicans, may multiply, causing an infection due to an overgrowth of the fungi.

Tinea infections usually cause itchy, red, scaly, ring-shaped patches on the skin that spread easily. Hairs in the area of infection often fall out or break off, and the skin may crack. The skin may also develop a secondary bacterial infection. In tinea unguium, the nails discolor, crack, and thicken. Tinea versicolor may cause pigment changes in the skin that persist for up to a year.

Systemic fungal infections develop slowly. Symptoms often may be nonexistent, or there may be only the feeling of having a cold or the flu. Coughing, a fever, chest pain, chills, weight loss, and difficulty with breathing may become evident. Additional symptoms depend on the type and site of the infection.

Fungal infections are more common and more severe in people taking antibiotics, corticosteroids, immunosuppressant drugs, and contraceptives. This is also the case in people with endocrine disorders, immune diseases, and other conditions such as obesity, AIDS, tuberculosis, major burns, leukemia, and diabetes mellitus. Fungal infections often occur due to the use of antibiotic drugs for other conditions, because antibiotics kill off the bacteria that normally keep fungi at bay.