Background: Epidemiologic and experimental data suggest that estrogen has a salutary effect on Trichomonas vaginalis.
Case: A metronidazole-allergic postmenopausal woman was cured of vaginal trichomoniasis in association with discontinuation of estrogen replacement therapy.
Conclusion: Hormonal manipulation should be studied for the management of women with trichomoniasis who are allergic to metronidazole or who are infected with metronidazole-resistant strains of Trichomonas vaginalis.