Approach to vaginal discharge Quiz: Ace Your Exams

A 26-year-old woman comes to the clinic for evaluation of vaginal discharge with a “fishy” odor for 4 days. The patient is sexually active with multiple biologically male partners. She does not use condoms, and her last sexual encounter was one week ago. Her last menstrual period was 2 weeks ago. Medical history is noncontributory, and she takes no medication. Vital signs are within normal limits. Physical examination shows normal-appearing external genitalia with no erythema. Pelvic examination shows thin gray-white vaginal discharge with odor. The cervix appears normal and there is no cervical motion tenderness. A pregnancy test is negative. Vaginal pH is 4.8. Wet mount is shown below. No hyphae are seen on potassium hydroxide preparation. A “whiff” test is positive. Which of the following is the most likely diagnosis?
 
^{Reproduced from: Wikimedia Commons}