infection with Trichomonas vaginalis, a protozoan flagellate, usually transmitted through sexual intercourse

infection with Candida albicans (Monilia), a fungus that requires glucose for growth (Incidence rises during the secretory phase of the menstrual cycle. Such infection occurs twice as often in pregnant females as in nonpregnant females. It also commonly affects users of hormonal contraceptives, diabetics, and patients receiving systemic therapy with broad-spectrum antibiotics [incidence may reach 75%].)

infection with Gardnerella vaginitis, a gram-negative bacillus

venereal infection with Neisseria gonorrhoeae (gonorrhea), a gram-negative diplococcus

viral infection with venereal warts (condylomata acuminata) or herpes-virus Type II, usually transmitted by sexual intercourse

vaginal mucosa atrophy in meno-pausal women due to decreasing levels of estrogen, which predisposes to bacterial invasion.

parasitic infection (Phthirus pubis [crab louse])

trauma (skin breakdown may lead to secondary infection)

poor personal hygiene

chemical irritations, or allergic reactions to hygiene sprays, douches, detergents, clothing, or toilet paper

vulval atrophy in menopausal women due to decreasing estrogen levels

retention of a foreign body, such as a tampon or diaphragm.