This opportunistic infection occurs in individuals who have weakened immune systems, such as HIV patients. HIV infects and destroys the body's immune cells, especially the CD4 cells. The patient's CD4 cell count is used as a marker to determine how far the HIV has progressed. Individuals with a CD4 cell count lower than 200 cells per microliter of blood have progressed to AIDS.
Candida albicans is present in most people's mouths. HIV patients who carry the fungus typically develop oral thrush once their CD4 cell count drops below 350.
Esophageal candidiasis occurs when oral thrush spreads into the esophagus. This infection typically occurs when the HIV patient's CD4 cell counts are 200 or less. According to the U.S. Centers for Disease Control and Prevention (CDC), esophageal candidiasis is considered an AIDS-defining illness. This means that the infection is often a sign that the patient's condition has progressed from HIV to AIDS.
Vaginal candidiasis (yeast infection) is common in both immunocompetent and immunocompromised individuals. Small amounts of Candida albicans are present in most women's vaginas. The fungus can overgrow if the environment in the vagina changes. For instance, vaginal candidiasis is associated with pregnancy, high-estrogen oral contraceptives (like birth control pills), uncontrolled diabetes mellitus, tight-fitting clothes, antibiotic therapy, dietary factors, intestinal colonization, and sexually transmitted diseases.
Oral thrush: Symptoms of oral thrush may develop suddenly. Oral thrush typically causes creamy white lesions on the tongue, inner cheek, and sometimes the gums, tonsils, and roof of the mouth. These lesions are often painful in HIV patients, and they may bleed slightly when they are rubbed.
Esophageal candidiasis: Severe cases of oral thrush may spread into the esophagus. This is most likely to occur if oral thrush is left untreated or if the patient is extremely immunocompromised. Common symptoms of esophageal candidiasis include pain or difficulty swallowing and sensation of food sticking to the throat. The pain may be so severe that it is difficult to eat. A fever may indicate that the infection has spread beyond the esophagus.
Vulvovaginal candidiasis (yeast infection): Symptoms of vulvovaginal candidiasis (yeast infection) generally worsen during menstruation because the hormonal changes provide a suitable environment for fungal growth. Common symptoms include itching, watery or curd-like vaginal discharge that is white in color, vaginal erythema (reddening of the skin), dyspareunia (pain during sexual intercourse), external dysuria (painful urination), swollen labia and vulva, and vaginal lesions.
General: In most cases, diagnoses of candidiasis infections can be determined after a physical examination. If a diagnosis is uncertain, the physician may scrape surface cells of the mouth, esophagus or vagina (depending on where symptoms are) or culture a tissue sample to determine whether the fungus is present.
Throat culture: A throat culture is often used to diagnosis oral candidiasis. During the procedure, a physician swabs the back of the patient's throat with a sterile cotton swab. The tissue sample is then cultured on a special medium to determine the bacteria or fungi that may be causing the symptoms. If Candida albicans is present, a positive diagnosis for candidiasis is made.
Endoscopic examination: An endoscopic examination may be conducted to diagnosis esophageal candidiasis. During the procedure, an endoscope (thin, flexible tube with a camera attached to it) is inserted into the throat. The doctor then takes a sample of tissue (either a biopsy or brushing) from the esophagus to be examined in a laboratory for the presence of fungus. The procedure generally takes between 30 and 60 minutes. Patients are typically given a sedative and a local anesthetic.
Barium swallow: A barium swallow test may be conducted to diagnosis esophageal candidiasis. During the test, the patient drinks one or two barium "milkshakes." Barium is a chalky liquid that coats the internal organs so that they are more visible on the X-ray. This substance helps the radiologist see the esophagus and stomach during an X-ray. Esophageal candidiasis may be indicated if lesions appear in the esophagus.
Vaginal discharge tests: Vaginal discharge can be analyzed under a microscope or cultured to determine whether the fungus is present. During a microscopic evaluation, a sample of vaginal discharge is placed on a microscope slide with a drop of 10% potassium hydroxide (KOH) solution. The KOH solution dissolves all of the cells except for fungus cells. If the Candida albicans fungus is present in high numbers, candidiasis is strongly suspected
During a culturing procedure, a swab is rubbed on the infected skin surface. The sample is then placed on a sterile Petri dish and allowed to grow in a laboratory to determine the bacteria or fungi that may be causing the symptoms.