Snapshot A 26-year-old G0 woman with last menstrual period 5 days ago who presents to her gynecologist for fishy-smelling vaginal discharge. She currently has multiple sexual partners and does not use consistent protection. She also requests to be tested for sexually transmitted diseases. On pelvic exam, she has a thin, malodorous gray vaginal discharge that coats the vaginal wall smoothly. Her vulva is not erythematous or edematous. On wet mount microscopy, clue cells are visualized. She is started on antibiotics. Introduction Classification Gardnerella vaginalis facultative anaerobic gram-variable pleomorphic rod catalase-negative oxidase-negative causes bacterial vaginosis not a sexually transmitted disease but is associated with sexual activity Epidemiology incidence very common demographics women risk factors immunosuppression use of antibiotics vaginal douching having multiple sexual partners having unprotected sex Pathogenesis decreased percentage of normal vaginal flora with lactobacillus that produces hydrogen-peroxide dominance of G. vaginalis and other anaerobic bacteria Associated conditions HIV infection herpes simplex virus type 2 urinary tract infection Presentation Symptoms often asymptomatic Physical exam thin and gray/white vaginal discharge coats the vaginal wall vaginal malodor (fishy) vulva is normal Studies Labs wet mount microscopy > 20% clue cells in vaginal discharge vaginal epithelial cells that are covered with bacteria whiff test fishy odor after addition of 10% potassium hydroxide vaginal pH > 4.5 Making the diagnosis based on clinical presentation and laboratory studies Differential Vulvovaginal candidiasis distinguishing factors thick white curd-like vaginal discharge often very itchy with vulvar erythema and edema Trichomoniasis distinguishing factors green vaginal discharge burning sensation with dysuria and dyspareunia postcoital bleeding vulvar erythema Treatment Management approach mainstay of treatment is antibiotics encourage patients to avoid douching Medical metronidazole or clindamycin indication all patients Complications Endometritis after gynecologic procedures Miscarriage Spontaneous abortion