Trichomoniasis is a common sexually transmitted infection caused by the parasite Trichomonas vaginalis. Many people have no symptoms, but it can cause vaginal or urethral irritation and raises the risk of HIV and of preterm birth.
Key symptoms
- Frothy yellow-green vaginal discharge with a fishy odor
- Vaginal itching, burning and pain with sex
- Pain or burning when urinating
- Men often have no symptoms or a mild urethral discharge
What you find on exam
- Red, irritated vulva and vagina
- Small red spots on the cervix (strawberry cervix) in some patients
- Discharge pooled in the vagina; look for signs of other STIs
- Vaginal pH above 4.5
Tests
- NAAT on a vaginal swab, urine or urethral swab: the preferred test
- Wet mount: moving pear-shaped parasites, but it misses many cases
- Testing for other STIs: chlamydia, gonorrhea, syphilis and HIV
- Retest about 3 months after treatment
Treatment basics
- Women: metronidazole 500 mg twice a day for 7 days
- Men: metronidazole 2 g as a single dose
- Treat sex partners and avoid sex until both are treated and symptoms are gone
- Metronidazole is safe to use in pregnancy
Red flags
- Pelvic pain or fever, which suggests pelvic inflammatory disease
- Symptoms during pregnancy
- Symptoms that persist after treatment
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Related guides
Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.