Illness script
Trichomoniasis
Sexually active woman with frothy, malodorous yellow-green discharge and a 'strawberry cervix'.
This illness script for Trichomoniasis covers the classic presentation, who it affects, how you work it up, the mechanism, and first-line treatment—written for USMLE Step 1 and clerkship clinical reasoning.
Updated Jul 18, 2026All scripts
01
Who it affects
- Sexually active adults, more symptomatic in women
- Most common non-viral STI worldwide
- Risk: multiple partners, other STIs, unprotected sex
- Higher prevalence in older women and lower socioeconomic groups
02
Diagnostics & workup
- History: frothy discharge, vulvar itching, dysuria, dyspareunia
- Exam: 'strawberry cervix' (punctate hemorrhages), vaginal erythema
- Vaginal pH >4.5
- NAAT is gold standard (most sensitive)
- Wet mount: motile flagellated trichomonads (low sensitivity)
- Whiff test may be positive
03
Pathophysiology
- Trichomonas vaginalis — flagellated anaerobic protozoan
- Sexually transmitted, adheres to squamous epithelium
- Causes local inflammation and microhemorrhages
- Increases HIV transmission risk; linked to preterm birth
04
Treatment
- Metronidazole 2g PO single dose OR 500mg BID x7 days
- Tinidazole is alternative
- Treat all sexual partners simultaneously
- Avoid alcohol during and 24-72h after (disulfiram reaction)
- Test-of-cure recommended in women within 3 months
- Screen for coexisting STIs (HIV, gonorrhea, chlamydia)
Keep reading
Full library- Third-Trimester Antepartum HemorrhageVaginal bleeding after 20 weeks gestation, classically from placenta previa (painless) or abruption (painful).
- Urge IncontinenceSudden strong urge to void followed by involuntary urine leakage, often with frequency and nocturia.
Educational use only. This illness script is a study framework, not medical advice. Confirm decisions with current guidelines and your clinical supervisors.