A 24-year-old woman comes to the office due to postcoital bleeding for the past week. She has had 3 new male sexual partners over the last 6 months and uses condoms inconsistently. The patient has mild, persistent asthma for which she takes low-dose, inhaled glucocorticoids. She is also taking oral contraceptives, and her last menstrual period was 3 weeks ago. Vital signs are normal. Pelvic examination shows a thin, malodorous vaginal discharge and erythema of the vulva and vaginal mucosa. The cervix is erythematous and has multiple macular lesions that easily bleed when probed with a cotton swab. Wet mount microscopy of the discharge shows motile, ovoid-shaped organisms. Urine pregnancy test is negative. Which of the following is the most appropriate treatment for this patient?
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This patient has trichomoniasis, which is a common sexually transmitted infection caused by Trichomonas vaginalis, a flagellated, motile protozoan that can result in cervical and vaginal infections (although many patients are asymptomatic). Trichomoniasis commonly causes vaginitis, which results in a thin, malodorous discharge with an elevated pH (>4.5) and vulvovaginal erythema (eg, vulvar pruritus). It can also cause acute cervicitis, resulting in postcoital bleeding and dyspareunia from friable, macular cervical lesions (eg, punctate hemorrhages, "strawberry cervix"). Diagnosis is via visualization of motile, ovoid-shaped organisms on wet mount microscopy or with nucleic acid amplification testing.
First-line treatment for trichomoniasis is with oral metronidazole or tinidazole. Patients and their sexual partners should be treated, regardless of symptoms, because there is a high rate of asymptomatic infection and low rates of compliance with delayed therapy. Individuals should refrain from sexual activity for a week (to prevent reinfection) and alcohol consumption (due a possible disulfiram-like reaction) after treatment.
(Choice A) Acyclovir treats herpes simplex virus, which causes painful genital vesicles or ulcerations rather than vaginitis symptoms.
(Choices B and C) Boric acid and clindamycin may be used in the treatment of recurrent bacterial vaginosis. Patients have a thin vaginal discharge with no associated vulvar erythema or cervical friability; microscopy shows clue cells rather than motile organisms.
(Choice D) Doxycycline may be used to treat Chlamydia trachomatis cervicitis, which presents with cervical friability (eg, postcoital bleeding) and a purulent cervical discharge. However, microscopy shows polymorphonuclear leukocytes rather than motile organisms.
(Choice E) Fluconazole is used in the treatment of Candida vulvovaginitis, an infection that can occur with recent corticosteroid use; however, patients typically have a thick, white vaginal discharge, and microscopy shows pseudohyphae.
(Choice G) Penicillin G benzathine is used to treat syphilis, which typically presents with vulvar lesions (eg, chancre, condyloma lata). Syphilis does not cause vaginitis or cervicitis symptoms.
Educational objective:
Trichomonas vaginalis is a common sexually transmitted infection that presents with a thin, malodorous vaginal discharge; cervical friability; and motile, ovoid-shaped organisms on microscopy. Patients and their sexual partners are treated with oral metronidazole and should abstain from sexual activity for a week until treatment has been completed to prevent reinfection.