Fungal Infections

Fungal Infections

What Are Fungal Infections?

What Are the Common Signs and Symptoms of Fungal Infections?

What Are Some Specific Fungal Infections?

How Common Are Fungal Infections?

Are They Contagious?

How Do Doctors Make the Diagnosis?

Can Fungal Infections Be Treated?

Can Fungal Infections Be Prevented?

Resources

Fungal (FUNG-gul) infections are caused by fungi (FUNG-eye) that can grow on the skin, nails, and hair and within internal organs.

KEYWORDS

for searching the Internet and other reference sources

Aspergillosis

Blastomycosis

Candidiasis

Coccidioidomycosis

Cryptococcosis

Fungi

Histoplasmosis

Molds

Mycoses

Mycology

Sporotrichosis

Tinea

Yeasts

What Are Fungal Infections?

Fungal infections are caused by fungi, tiny microbes* found in soil, air, and water, as well as on plants, animals, and people. There are at least 100,000 species of fungi. The most familiar types are the mushrooms that some people like to eat on pizza, the fuzzy white or blue-green mold that grows on forgotten foods in the back of the refrigerator, and the mildew on the shower curtain. Fungi grow best in warm, moist areas, like a steamy bathroom or the spaces between the toes.

*microbes

(MY-krobes) are microscopic living organisms, such as bacteria, viruses and fungi.

Relatively few species of fungi cause fungal infections, also called mycoses (my-KO-seez). Those that produce infection can cause two basic types: superficial and systemic infections. Superficial infections are found on the skin, nails, or hair and usually are not serious. Systemic infections take hold inside the body, in individual organs or throughout the body, and can be severe. Systemic infections are more likely to appear in people who have weak immune systems, such as those who have cancer or AIDS*. In these people, the infections can cause chronic* disease and, in some cases, death.

*AIDS ,

or acquired immunodeficiency (ih-myoo-no-dih-FIH-shen-see) syndrome, is an infection that severely weakens the immune system; it is caused by the human immunodeficiency virus (HIV).

*chronic

(KRAH-nik) means continuing for a long period of time.

What Are the Common Signs and Symptoms of Fungal Infections?

Superficial fungal infections, such as jock itch, vaginal yeast infection, athlete’s foot, and ringworm, typically are annoying but not very serious. Their symptoms generally include itchy, dry, red, scaly, or irritated skin. Systemic fungal infections often begin in the lungs and take time to develop. Severe infections occur in people whose immune systems have been weakened, allowing the infection to spread beyond the lungs to other organs. Symptoms of systemic fungal infections depend on which organs become infected and may include respiratory problems, extreme tiredness, coughing, weight loss, fever, night sweats, and headache.

What Are Some Specific Fungal Infections?

Tinea (TIH-nee-uh) is a general term given to a group of superficial fungal infections that affect the nails, feet (athlete’s foot), groin area (jock itch), scalp, or skin (ringworm). Trichophyton and Microsporum fungi cause these related infections. Ringworm is identified by a red, scaly patch on the skin that looks like an expanding ring around a clearing center. Symptoms of athlete’s foot include redness and cracking of the skin between the toes, and infected nails on the hands or feet usually look white and appear to be crumbling.

Candidiasis (kan-dih-DYE-uh-sis) is a superficial fungal infection caused by various strains of Candida (CAN-dih-duh) fungi. Candida is a yeastlike fungus often found in the mouth and the lining of the intestinal tract of healthy people. In people with weak immune systems, however, it can grow out of control, leading to an infection. A Candida infection of the mouth and throat is known as oropharyngeal (or-oh-fair-in-JEE-ul) candidiasis (OPC) or thrush, and infection of the vagina is known as vulvovaginal (vul-vo-VAH-jih-nul) candidiasis (VVC) or vaginal yeast infection. OPC can affect newborns, people with AIDS or diabetes*, and other people with weak immune systems. Its symptoms include white, thick patches on the tongue, mouth, and throat. Candida infection commonly occurs in newborns in the form of thrush or diaper rash. VVC is associated with vaginal burning or itching and a thick, cheeselike discharge. In certain situations, Candida can enter the bloodstream and spread to internal organs. This is seen most frequently in hospitalized patients who have weak immune systems and have received antibiotics.

*diabetes

(dye-uh-BEE-teez) is a condition in which the body’s pancreas does not produce enough insulin or the body cannot use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination, dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within the body.

A yeast colony, as seen with an electron microscope, looks like growing vegetation. Custom Medical Stock Photo, Inc.

Aspergillosis (as-per-jih-LO-sis) is the name for a variety of systemic infections caused by Aspergillus (as-per-JIH-lus) fungi. If it is inhaled through the mouth or nose, the fungus can cause a mild allergic reaction or a more serious infection of the sinuses* and lungs. Symptoms of aspergillosis vary and may include fever, cough, chest pain, and wheezing. In severe cases, typically seen in people with weak immune systems, the infection can spread to other organs, including the brain, skin, and bones.

*sinuses

(SY-nuh-ses) are hollow, air-filled cavities in the facial bones.

Blastomycosis (blas-toh-my-KO-sis) is a systemic infection caused by the Blastomyces dermatitidis fungus commonly found in soil in the southeastern, midwestern, and south-central United States. The disease’s symptoms resemble those of the flu: joint and muscle pain, a cough that brings up sputum*, fever, chills, and chest pain. If it progresses, it can lead to chronic pulmonary* infection, causing permanent lung damage, or widespread disease that affects the bones, skin, and genital and urinary tracts. Blastomycosis leads to death in about 5 percent of patients.

*sputum

(SPYOO-tum) is a substance that contains mucus and other matter coughed out from the lungs, bronchi, and trachea.

*pulmonary

means referring to or pertaining to the lungs.

Cryptococcosis (krip-toh-kah-KO-sis) is a systemic infection caused by the fungus Cryptococcus neoformans, usually found in soil or bird droppings. Typically, the fungus enters the body through the mouth or nostrils when someone inhales fungi spores*, and symptoms of a lung infection, such as cough and chest pain, may develop. Although infection with Cryptococcus usually produces no symptoms or only mild symptoms in healthy people, the infection may spread in people who have weak immune systems. If it spreads to the central nervous system, it can cause inflammation of the membranes covering the brain and spinal cord. This is especially common among people with AIDS.

*spores

are a temporarily inactive form of a germ enclosed in a protective shell.

Histoplasmosis (his-toh-plaz-MO-sis) is usually a mild systemic infection caused by Histoplasma capsulatum. This fungus is found in the eastern and central United States in soil that contains bird and bat feces*. When the soil is disturbed, the fungal spores may be inhaled. Histoplasmosis can cause flulike symptoms, including body aches, fever, and cough. Most people who become infected do not experience symptoms, but as with other fungal infections, people with weak immune systems are at risk for severe disease. In those cases, the infection affects the lungs and may spread to the liver*, spleen*, bones, and brain.

*feces

(FEE-seez) is the excreted waste from the gastrointestinal tract.

*liver

is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.

*spleen

is an organ in the upper left part of the abdomen that stores and filters blood. As part of the immune system, the spleen also plays a role in fighting infection.

Sporotrichosis (spo-ro-trih-KO-sis) is a skin infection caused by the Sporothrix schenckii fungus, which is found in soil, thorny plants, hay, sphagnum (SFAG-num) moss, and other plant materials. It enters the skin through a small cut or puncture, such as a thorn might make. Soon, small reddish bumps resembling boils* form around the cut and often ulcerate*. In some cases, infection can spread to other parts of the body, such as the lungs or joints.

*boils

are skin abscesses, or collections of pus in the skin.

*ulcerate

means to become eroded by infection, inflammation, or irritation.

Friendly Bacteria

Naturally occurring “friendly” bacteria and fungi live side by side on the human body. Some bacteria help keep fungi in check by preventing them from reproducing uncontrollably and causing disease. From time to time, however, doctors need to prescribe antibiotics to combat not-so-friendly bacteria that cause illness. Most antibiotics kill many types of bacteria, both good and bad, and using them for long periods of time can destroy too many friendly bacteria, allowing fungi to grow unchecked and eventually cause infection. To preserve the bacteria we need, it is important to use antibiotics only when necessary and prescribed by a doctor.

Coccidioidomycosis (kok-sih-dee-oyd-o-my-KO-sis) is a systemic infection caused by Coccidioides immitis, a fungus found in soil in the southwestern United States, Mexico, and South America. Most people with coccidioidomycosis have no symptoms, but 40 percent of patients experience a flulike illness, with fever, rash, muscle aches, and cough. Also know as valley fever, the infection can cause pneumonia* or widespread disease affecting the skin, bones, and membranes covering the brain and spinal cord.

*pneumonia

(nu-MO-nyah) is inflammation of the lung.

How Common Are Fungal Infections?

Superficial fungal infections, such as athlete’s foot and candidiasis, are fairly common. Systemic infections, on the other hand, are rare, appearing in less than one to two people of every 100,000 in the United States, according to the U.S. Centers for Disease Control and Prevention. They are more common in certain populations, such as people with AIDS or those who have had organ transplants.

With the so-called endemic* mycoses, rates of disease are higher in specific geographic areas. For example, coccidioidomycosis occurs in about 15 of every 100,000 people in parts of the southwestern United States (with 10 to 50 percent of the population testing positive for exposure to the fungus). In areas where histoplasmosis is found, up to 80 percent of the population test positive for exposure to Histoplasma capsulatum, but the disease develops only in people with weak immune systems.

*endemic

(en-DEH-mik) describes a disease or condition that is present in a population or geographic area at all times.

Are They Contagious?

Some fungal infections, such as candidiasis and ringworm, can spread from person to person through contact with the infected area. Most infections, however, develop from fungi found naturally on the human body or in the environment. Many fungi that cause systemic respiratory disease are found in soil or in the droppings of animals or birds. Usually they are inhaled after the soil or droppings are disturbed, sending dust and fungal spores into the air.

How Do Doctors Make the Diagnosis?

Most superficial fungal infections are diagnosed based on their appearance and location. A doctor also may take a skin scraping to examine under the microscope or to culture* in a laboratory. Some fungi glow with a particular color under ultraviolet light, so a doctor may make the diagnosis by shining such a light on the affected area. Systemic infections can be diagnosed by collecting a sample of blood, urine, cerebrospinal fluid*, or sputum to culture.

*culture

(KUL-chur) is a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Over time, ranging from hours to weeks, the organisms will grow and can be identified.

*cerebrospinal

(seh-ree-bro-SPY-nuhl) fluid is the fluid that surrounds the brain and spinal cord.

Can Fungal Infections Be Treated?

Most superficial fungal infections are treated at home with antifungal creams or shampoos for 1 to 2 weeks. Oral (taken by mouth) antifungal medication also may be prescribed, if necessary. Some cases of fungal infection last for a while and may need to be treated with medicine for 2 to 4 weeks or even longer. Systemic illnesses often require hospitalization so that the patient can receive intravenous* antifungal drugs and supportive care.

*intravenous

(in-tra-VEE-nus) means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin’s surface directly into a vein.

Can Fungal Infections Be Prevented?

Preventing fungal infections can be difficult, because fungi are everywhere. In general, people who are otherwise healthy rarely contract systemic fungal infections. Practicing good hygiene, keeping the skin dry, and changing socks and underwear every day can help prevent superficial skin infections.

See also

Coccidioidomycosis (Valley Fever)

Skin and Soft Tissue Infections

Resources

Organization

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC provides fact sheets and other information on fungal infections through its website.

Telephone 800-311-3435 http://www.cdc.gov

Website

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including fungal infections.

http://www.KidsHealth.org