Bacteria thrive in an environment with lots of sugar. That's why people with diabetes are often prone to yeast infections. Common infection sites include the mouth (called "oral thrush") and places where you sweat, like the armpits, the skin between your toes, and under the breasts. Women with diabetes may also have more frequent vaginal and urinary tract infections. Itchy skin, a rash, white patches in your mouth, and vaginal itching, pain, and discharge are some of the most common signs of a yeast infection.