Candidiasis is a fungal infection caused by several species of the yeast 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 medications may be applied directly to the affected area or taken by mouth, but serious infections require medications given by vein.
Candida are yeast that are normally present on the skin, in the intestinal tract, and in the genital area. Usually, Candida in these areas does not cause problems. However, the fungi sometimes cause skin infections, mouth infections (affecting the mucous membranes), or infections of the vulva and vagina. Such infections can develop in people with a healthy immune system, but they are more common among or persistent in people with diabetes, cancer, or AIDS and in pregnant women. Candidiasis of the mouth and esophagus are common among people with AIDS. Candidiasis is also common among people who are taking antibiotics because the antibiotics kill the bacteria that normally live in the body and compete with Candida, allowing Candida to grow unchecked.
Candidiasis is bothersome but rarely life threatening. However, some forms of candidiasis are serious. They include
Invasive candidiasis
Candidemia (the most common form of invasive candidiasis)
(See also Overview of Fungal Infections, Candidiasis (Yeast Infection) of the skin, and Vaginal Yeast Infection.)
In invasive candidiasis, the infection spreads to other parts of the body, such as the heart valves, brain, spleen, kidneys, and eyes. Invasive candidiasis occurs mainly in people with a weakened immune system and in hospitalized people. Candidiasis is one of the most common infections acquired in the hospital.
Candidiasis of the esophagus is one of the illnesses indicating that HIV infection has developed into AIDS (called an AIDS-defining illness).
Candidemia is when candidal infection spreads through the bloodstream. It is a serious infection. In the United States, Candida is a common cause of bloodstream infections. The risk of developing this infection is increased by certain conditions, such as the following:
Major surgery
Use of intravenous lines or tubes—particularly a tube inserted into one of the large veins of the neck, upper chest, or groin (central venous catheter) or a tube used to provide nutrition (intravenous feeding)
Use of certain antibiotics
Candidemia is often fatal if not promptly treated.
Symptoms of Candidiasis
Infection of the mouth (thrush) causes the following:
Creamy, white, painful patches inside the mouth
Cracking at the corners of the mouth (cheilitis)
A red, painful, smooth tongue
In candidiasis of the mouth, white, painful patches form in the mouth—for example, under dentures (top photo) or on the tongue (bottom photo).
Images courtesy of Jonathan Ship, MD.
In candidiasis of the mouth, white, painful patches may form on the inside of the lips.
© Springer Science+Business Media
In candidiasis of the mouth, white, painful patches may form on the tongue.
© Springer Science+Business Media
In candidiasis of the mouth, white, painful patches form in the mouth—for example, under dentures (top photo) or on the tongue (bottom photo).
Images courtesy of Jonathan Ship, MD.
In candidiasis of the mouth, white, painful patches may form on the inside of the lips.
© Springer Science+Business Media
In candidiasis of the mouth, white, painful patches may form on the tongue.
© Springer Science+Business Media
Patches in the esophagus cause pain or difficulty swallowing.
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 of Candidiasis
Examination and sometimes culture of a sample of blood or infected tissue
Sometimes blood tests
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.
Doctors may do a blood test called the T2Candida Panel to detect Candida in the blood quickly and accurately. Other tests that detect genetic material in microorganisms may be done, including polymerase chain reaction (PCR). The PCR test is used to produce many copies of a gene from a microorganism, making the microorganism much easier to identify.
If candidemia is diagnosed, doctors may examine the eyes to determine whether the eyes are infected.
Treatment of Candidiasis
Antifungal medications
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.
