When you mention the word yeast, most people think of the helpful little organisms that help bread dough to rise before we bake it. But, when a different species of yeast, called Candida albicans, has a "growth spurt" on our skin, the consequences are much more unpleasant than opening an oven and pulling out a fresh loaf of homemade bread.
Candida albicans yeast is a type of fungus that is found on our skin normally, but only causes trouble when there is an overgrowth. Especially in hot, humid weather, areas of the body such as the armpits, groin, and the underneath of women's breasts, where skin touches skin, can become moist and warm enough to provide a perfect environment for an overgrowth to occur. Obese people with skin that folds over, and diabetics are particularly susceptible to this, as are those with poor hygiene or depressed immune systems. Candida infections, especially of the mouth or vagina, can also occur in people who have been on a long course of antibiotics.
If a Candida rash develops in a skin fold, it's called intertrigo, and it usually has a very characteristic appearance, and is easily diagnosed by a physician. But in cases where there is doubt, the doctor may scrape a small area of skin cells off to test and view under a slide. Candidiasis of the mouth and throat is called thrush, and is more common in those with chronic disease. Cheilitis is a softening of the corners of the mouth at the creases. Candida is also the most common cause for diaper rash.
Treatment for the condition is usually topical, with the application of an antifungal cream such as clotrimazole or miconazole, but may also involve antibiotic therapy if a secondary infection is discovered. Oral antifungal medications may be necessary for nail bed infection, or severe candida infections in other parts of the body.