Candidiasis is an infection caused by Candida fungi, especially Candida albicans. These fungi are found almost everywhere in the environment. Some may live harmlessly along with the abundant "native" species of bacteria that normally colonize the mouth, gastrointestinal tract and vagina. Usually, Candida is kept under control by the native bacteria and by the body's immune defenses. If the mix of native bacteria is changed by antibiotics, the body moisture that surrounds native bacteria can also have subtle changes in its acidity or chemistry. This can cause yeast to grow and to stick to surfaces, so that the yeast causes symptoms. Candida infections can cause occasional symptoms in healthy people. If a person's immune system is weakened by illness (especially AIDS or diabetes), malnutrition, or certain medications (corticosteroids or anticancer drugs), Candida fungi can cause symptoms more frequently. Candidiasis can affect many parts of the body, causing localized infections or larger illness, depending on the person and his or her general health.
Types of candidiasis include:
- Thrush. Thrush is the common name for a mouth infection caused by the Candida albicans fungus. It affects moist surfaces around the lips, inside the cheeks, and on the tongue and palate. Thrush is common in people with diseases such as cancer and AIDS, which both suppress the immune system. Thrush can develop in people with normal immune systems, too, particularly in people with diabetes or long-lasting irritation from dentures.
- Cutaneous (skin) candidiasis. Candida can cause skin infections, including diaper rash, in areas of skin that receive little ventilation and are unusually moist. Some common sites include the diaper area; the hands of people who routinely wear rubber gloves; the rim of skin at the base of the fingernail, especially for hands that are exposed to moisture; areas around the groin and in the crease of the buttocks; and the skin folds under large breasts.
- Vaginal yeast infections. Vaginal yeast infections are not usually transmitted sexually. During a lifetime, 75% of all women are likely to have at least one vaginal Candida infection, and up to 45% have 2 or more. Women may be more susceptible to vaginal yeast infections if they are pregnant or have diabetes. The use of antibiotics or birth control pills can promote yeast infections. So can frequent douching.
- Deep candidiasis (for example, candida sepsis). In deep candidiasis, Candida fungi contaminate the bloodstream and spread throughout the body, causing severe infection. This is especially common in newborns with very low birth weights and in people with severely weakened immune systems or severe medical problems. In these people, Candida fungi may get into the bloodstream through skin catheters, tracheostomy sites, ventilation tubing, or surgical wounds. Deep candidiasis also can occur in healthy people if Candida fungi enter the blood through intravenous drug abuse, severe burns or wounds caused by trauma.
Candidiasis causes different symptoms, depending on the site of infection.
- Thrush. Thrush causes curd-like white patches inside the mouth, especially on the tongue and palate and around the lips. If you try to scrape off this whitish surface, you will usually find a red, inflamed area, which may bleed slightly. There may be cracked, red, moist areas of skin at the corners of the mouth. Sometimes thrush patches are painful, but often they are not.
- Esophagitis. Candida esophagitis may make swallowing difficult or painful, and it may cause chest pain behind the breastbone (sternum).
- Cutaneous candidiasis. Cutaneous candidiasis causes patches of red, moist, weepy skin, sometimes with small pustules nearby.
- Vaginal yeast infections. Vaginal yeast infections may cause the following symptoms: vaginal itch and/or soreness; a thick vaginal discharge with a texture like soft or cottage cheese; a burning discomfort around the vaginal opening, especially if urine touches the area; and pain or discomfort during sexual intercourse.
- Deep candidiasis. When Candida spreads to the bloodstream, it may cause a wide range of symptoms, from unexplained fever to shock and multiple organ failure.
Your doctor will ask about your medical history, including diabetes, cancer, HIV, and other chronic illnesses. He or she also will ask about your diet and about your recent use of antibiotics or medications that can suppress the immune system. If your doctor suspects cutaneous candidiasis, he or she may ask how you care for your skin and about conditions that expose your skin to excessive moisture, such as using rubber gloves.
Often, your doctor can diagnose thrush, cutaneous candidiasis, or vaginal yeast infection by a simple physical examination. However, if the diagnosis is uncertain, your doctor may scrape the surface to obtain cells to examine under a microscope or may culture a skin sample to identify fungus (yeast). A culture is especially helpful if you have a yeast infection that returns after treatment. In this case, the culture can help identify whether the yeast is resistant to usual antibiotic treatments. If your doctor suspects that you have an undiagnosed medical illness that increases your risk of candidiasis -- such as diabetes, cancer or HIV -- blood tests or other procedures may be necessary.
To diagnose Candida esophagitis, your doctor will examine your esophagus with an endoscope, a flexible instrument that is inserted into your throat and allows your doctor look at the area directly. During this examination, called endoscopy, your doctor will take a sample of tissue (either a biopsy or a "brushing") from your esophagus to be examined in a laboratory.
To diagnose deep candidiasis, your doctor will draw a sample of blood to be checked in a laboratory for the growth of Candida fungi or other infectious agents.
In otherwise healthy people who have thrush, cutaneous candidiasis, or vaginal yeast infections, Candida infections usually can be eliminated with a short treatment (sometimes a single dose) of antifungal medication. However, in people with AIDS or other diseases that weaken the immune system, Candida infections can be difficult to treat and can return after treatment. In people with weakened immune systems, candidiasis can be life threatening if it passes into the blood and spreads to vital organs.
In general, you can prevent most Candida infections by keeping your skin clean and dry, by using antibiotics only as your doctor directs, and by following a healthy lifestyle, including proper nutrition. People with diabetes should try to keep their blood sugar under tight control.
If you have HIV or another cause of recurrent episodes of thrush, then antifungal drugs such as clotrimazole (Lotrimin, Mycelex) can help to minimize flare-ups.
Treatment of candidiasis varies, depending on the area affected:
- Thrush. Doctors treat thrush with topical, antifungal medications such as nystatin (Mycostatin and others) and clotrimazole. For mild cases, a liquid version of nystatin can be swished in the mouth and swallowed, or a clotrimazole lozenge can be dissolved in the mouth. For more severe cases, fluconazole (Diflucan) can be taken once a day by mouth.
- Esophagitis. Candida esophagitis is treated with an oral anti-fungal drug such as fluconazole.
- Cutaneous candidiasis. This skin infection can be effectively treated with a variety of antifungal powders and creams. The affected area must be kept clean and dry and protected from chafing.
- Vaginal yeast infections. Vaginal yeast infections can be treated with antifungal medications that are applied directly into the vagina as tablets, creams, ointments or suppositories. These include butoconazole (Femstat), clotrimazole (Gyne-Lotrimin), miconazole (Monistat, Vagistat and others), nystatin (Mycostatin and others), and tioconazole (Monistat-1, Vagistat-1). A single dose of oral fluconazole can be used. Sex partners usually do not need to be treated.
- Deep candidiasis. This infection is usually treated with intravenous fluconazole. People with very low white blood cell counts may need an alternative intravenous anti-fungal drug, such as caspofungin or micafungin.
Call your doctor whenever you have symptoms of candidiasis, if you have a chronic illness or a weakened immune system caused by cancer, HIV or medications that suppress the immune system.
Women that are otherwise healthy can self-treat for simple candida vaginitis. Call your doctor if it persists despite topical therapy or it recurs soon after treatment.
Typically, in otherwise healthy people with superficial candidiasis, a properly treated infection goes away without leaving permanent damage. Superficial candidiasis may return if a prolonged course of antibiotics is needed or there is a change in your overall health.
In people with chronic illnesses or weakened immune systems, episodes of candidiasis may be more resistant to treatment and may return after treatment ends. In people with deep candidiasis, those who are diagnosed quickly and treated effectively have the best prognosis, especially if their infection can be stopped before it spreads to major organs.
Centers for Disease Control and Prevention (CDC)
1600 Clifton Road
Atlanta, GA 30333
National Oral Health Information Clearinghouse
1 NOHIC Way
Bethesda, MD 20892-3500