Candidiasis can occur in the mouth, esophagus (throat), digestive tract, vagina or on the skin. The most common site of infection is in the mouth (thrush) and/or vagina (yeast infections, vaginitis). Among women, vaginal candidiasis appears as the most common symptom. Although vaginal candidiasis is slightly more common among HIV-positive women than negative women, there is no clear relationship between its occurrence and CD4+ cell count. Thus, the relationship between vaginal candidiasis and HIV infection remains unclear. Finally, esophageal candidiasis has been reported as the most common AIDS-defining OI, probably due to the decreased incidence of other OIs.
Symptoms of vaginal candidiasis include itching, vaginal swelling and thick and odorous discharge. Vaginal candidiasis is often associated with pregnancy, high estrogen oral contraceptives, diabetes, antibiotics use, tight-fitting clothes, dietary factors and sexually transmitted disease.
Esophageal candidiasis tends to occur more frequently when CD4+ cell counts are below 100. It is usually accompanied by thrush and esophageal/throat pain.
Systemic therapies can be used for any type of candidiasis. They must be used for esophageal candidiasis or candidiasis that has spread throughout the body. Intravenous treatment is generally the least desired option because it can have many side effects. It is left as a last resort in rare but serious, life-threatening cases that have not responded to other treatments.
Resistance to azole drugs has often required treatment with amphotericin B (Fungizone). While potent and effective, amphotericin B -- both intravenous and oral formulas -- is toxic, especially to the kidney. Newer liposomal versions of the drug, such as amphotericin B lipid complex or ABLC, have proven less toxic to the kidneys than its earlier formula.
A recent study compared the original form of the drug to the newer form in people who could not tolerate conventional amphotericin B and/or who did not respond to the drug. The study found that people were more likely to tolerate ABLC and were thus more likely to be able to take the drug until their fungal infection successfully cleared. Even among people with some underlying kidney disease, ABLC was better tolerated, resulting in only very small changes in kidney function tests.
More recently studies have shown that exposure to azole treatment (including fluconazole, ketoconazole and itraconazole) results in the decreased antifungal activity of amphotericin B. This will likely be the case for newer, less toxic forms of the drug; but more studies are needed to confirm this. Like the quandary created by anti-HIV drug resistance, the development of antifungal resistance underlines the importance of developing new classes of drugs that can effectively treat candidiasis.
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