Vaginal Yeast Infection Vaginal yeast infection or vulvovaginal candidiasis is a common cause of vaginal irritation. Doctors estimate that approximately 75 percent of all women will experience at least one symptomatic yeast infection during their lifetimes. Yeast are always present in the vagina in small numbers, and symptoms only appear with overgrowth. Several factors are associated with increased symptomatic infection in women, including pregnancy, uncontrolled diabetes mellitus, and the use of oral contraceptives or antibiotics. Other factors that may increase the incidence of yeast infection include using douches, perfumed feminine hygiene sprays, and topical antimicrobial agents, and wearing tight, poorly ventilated clothing and underwear. Whether or not yeast can be transmitted sexually is unknown. Because almost all women have the organism in the vagina, it has been difficult for researchers to study this aspect of the natural history.

Symptoms. The most frequent symptoms of yeast infection in women are itching, burning, and irritation of the vagina. Painful urination and/or intercourse are common. Vaginal discharge is not always present and may be minimal. The thick, whitish-gray discharge is typically described as cottage-cheese-like in nature, although it can vary from watery to thick in consistency. Most male partners of women with yeast infection do not experience any symptoms of the infection. A transient rash and burning sensation of the penis, however, have been reported after intercourse if condoms were not used. These symptoms are usually self-limiting.

Diagnosis. Because few specific signs and symptoms are usually present, this condition cannot be diagnosed by the patient's history and physical examination. The doctor usually diagnoses yeast infection through microscopic examination of vaginal secretions for evidence of yeast forms.

Scientists funded by the National Institute of Allergy and Infectious Diseases (NIAID) have developed a rapid simple test for yeast infection, which will soon be available for use in doctors' offices. If such a test were available for home screening, it would help them to appropriately use yeast medication.

Treatment. Various antifungal vaginal medications are available to treat yeast infection. Women can buy some antifungal creams, tablets, or suppositories (butoconazole, miconazole, clotrimazole, and tioconazole) over the counter for use in the vagina. But because BV, trichomoniasis, and yeast infection are difficult to distinguish on the basis of symptoms alone, a woman with vaginal symptoms should see her physician for an accurate diagnosis before using these products.

Other products available over the counter contain antihistamines or topical anesthetics that only mask the symptoms and do not treat the underlying problem. Women who have chronic or recurring yeast infections may need to be treated with vaginal creams for extended periods of time. Recently, effective oral medications have become available. Women should work with their physicians to determine possible underlying causes of their chronic yeast infections. HIV-infected women may have severe yeast infections that are often unresponsive to treatment.