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Candidiasis (candidosis, moniliasis, yeast infection) is infection caused by several species of Candida, especially Candida albicans.

• The most common type of candidiasis is a superficial infection of the mouth, vagina, or skin that causes white or red patches and itching, irritation, or both.
• People whose immune system is weakened may have serious infections of the esophagus and other internal organs.
• A sample of infected material is examined under a microscope and sent for culture.
• Antifungal drugs may be applied to the surface or taken by mouth, but serious infections require drugs given by vein.

Candida is normally present on the skin, in the intestinal tract, and, in women, in the genital area. Usually, Candida in these areas does not cause problems. However, the fungi sometimes cause infection of the skin (see Fungal Skin Infections: Candidiasis), the mucous membranes of the mouth (see Lip and Tongue Disorders: Discomfort and see Periodontal Diseases: Gingivitis Due to Infections), or vagina (see Vaginal Infections and Pelvic Inflammatory Disease: Overview of Vaginal Infections). Such infections can develop in people with a healthy immune system, but they are more common or persistent in people with diabetes, cancer, or AIDS and in pregnant women. Candidiasis is also common among people who are taking antibiotics because the antibiotics kill the bacteria that normally compete with Candida, allowing Candida to grow unchecked.

Some people, mainly those with a weakened immune system, develop candidiasis that spreads through the bloodstream (called candidemia) to other parts of the body, such as the heart valves, spleen, kidneys, and eyes. Without treatment, this infection progresses.

Symptoms

Infection of the mouth (thrush or trench mouth) causes the following:

• Creamy, white, painful patches inside the mouth
• Cracking at the corners of the mouth (cheilitis)
• A red, painful, smooth tongue

Patches in the esophagus cause pain during swallowing.f

Thrush

When the skin is infected, a burning rash develops. Some types of diaper rash are caused by Candida.

If the infection spreads to other parts of the body, it is more serious. It can cause fever, a heart murmur, enlargement of the spleen, dangerously low blood pressure (shock), and decreased urine production. An infection of the retina and inner parts of the eye can cause blindness. If the infection is severe, several organs may stop functioning, and death can occur.

Diagnosis

Many candidal infections are apparent from the symptoms alone. To confirm the diagnosis, a doctor must identify the fungi in a sample viewed under a microscope. Samples of blood or other infected tissues may be sent to a laboratory to be cultured and examined to identify the fungi.

Treatment

Candidiasis that occurs only on the skin or in the mouth or vagina can be treated with antifungal drugs (such as clotrimazoleSome Trade Names
LOTRIMIN AF MYCELEX
and nystatinSome Trade Names
MYCOSTATIN NILSTAT
) that are applied directly to the affected area. A doctor may prescribe the antifungal drug fluconazoleSome Trade Names
DIFULCAN
to be taken by mouth.

Candidiasis that has spread throughout the body is usually treated with amphotericin BSome Trade Names
FUNGIZONE
given intravenously. Other antifungal drugs—fluconazoleSome Trade Names
DIFULCAN
and related drugs (posaconazoleSome Trade Names
NOXAFIL
and voriconazoleSome Trade Names
VFEND
) or caspofunginSome Trade Names
CANCIDAS
and related drugs (micafunginSome Trade Names
MYCAMINE
and anidulafunginSome Trade Names
ERAXIS
)—are also effective.

Candidiasis is more serious and less responsive to treatment in people with certain disorders, such as diabetes. In people with diabetes, controlling blood sugar levels facilitates cure of the infection.

Last full review/revision October 2008 by Alan M. Sugar, MD