Yeast infection: Overgrowth of yeast can affect the skin (yeast rash), mouth (thrush), digestive tract, esophagus, vagina (vaginitis), and other parts of the body. Yeast infections occur most frequently in moist areas of the body. Although Candida albicans and other Candida yeasts are the most frequent offenders, other yeast groups are known to cause illness, primarily in immunocompromised patients. These include Torulopsis, Cryptococcus, Malassezia, and Trichosporon yeasts. Diagnosis is by observation, and can be confirmed by culturing a stool or mucosa sample, or a scraping from the affected area. Treatment is by topical or oral antifungal medications. Acidophilous, a helpful bacteria that normally helps to keep yeast in check, can also be tried in supplement form or in yogurt with live cultures.