What is the best course of action for a patient with a history of similar symptoms after unprotected sex, now presenting with unusual vaginal symptoms including metrorrhagia (unexpected bleeding), a slight odor, leukorrhea (white discharge), mild dysmenorrhea (cramps), and discomfort over the past week?

Evaluation and Management of Vaginal Symptoms After Unprotected Sex

This patient requires immediate diagnostic evaluation with vaginal pH testing, wet mount microscopy, and testing for sexually transmitted infections (STIs), followed by empiric treatment based on clinical findings while awaiting confirmatory results. 1

Immediate Diagnostic Workup

The combination of unexpected bleeding, odor, white discharge, and mild cramps after unprotected sex requires systematic evaluation to differentiate between bacterial vaginosis (BV), trichomoniasis, candidiasis, cervicitis, or pelvic inflammatory disease (PID). 2

Essential Point-of-Care Testing

• Vaginal pH measurement is the critical first step: pH >4.5 suggests BV or trichomoniasis, while pH ≤4.5 indicates candidiasis 1, 3
• Wet mount with saline should be examined for clue cells (stippled vaginal epithelial cells with obscured borders characteristic of BV) and motile trichomonads 1, 4
• 10% KOH preparation with whiff test: a fishy odor indicates BV or trichomoniasis 1, 4
• Cervical examination must assess for mucopurulent discharge, which suggests cervicitis from Chlamydia trachomatis or Neisseria gonorrhoeae 5, 2

Laboratory Testing Required

• Nucleic acid amplification testing (NAAT) for Chlamydia trachomatis and Neisseria gonorrhoeae is mandatory given the history of unprotected sex 5, 3
• Trichomonas testing via NAAT or culture, as wet mount only detects 50-75% of cases 4, 3
• Molecular diagnostic tests are superior to in-office microscopy for most clinicians 6

Most Likely Diagnoses and Treatment Algorithm

If pH >4.5 with Clue Cells and Fishy Odor: Bacterial Vaginosis

First-line treatment: Metronidazole 500 mg orally twice daily for 7 days (95% cure rate) 1, 7

• Alternative regimens include metronidazole gel 0.75% intravaginally twice daily for 5 days or clindamycin cream 2% intravaginally at bedtime for 7 days 1
• Do NOT use metronidazole 2g single dose for this patient, as it has a lower cure rate (84%) and is inadequate when symptoms are prominent 8, 1
• Advise the patient to avoid alcohol during treatment and for 24 hours after to minimize side effects 8
• Male partner treatment is NOT indicated as it does not prevent recurrence or alter clinical course 8, 9, 1

If Motile Trichomonads Identified: Trichomoniasis

Treatment: Metronidazole 500 mg orally twice daily for 7 days 6, 7

• Alternative single-dose regimen: Metronidazole 2g orally once 5, 10
• Sexual partner MUST be treated simultaneously to prevent reinfection 5, 7
• Patients should abstain from sex until both partners complete therapy and are asymptomatic 5
• Treatment failure is usually due to untreated male partners 4

If pH ≤4.5 with Yeast/Pseudohyphae: Vulvovaginal Candidiasis

Treatment: Fluconazole 150 mg orally as a single dose 3

• Alternative topical azole regimens include clotrimazole, miconazole, or terconazole intravaginally for 3-7 days 5, 3
• Partner treatment is NOT routinely indicated unless the male partner has symptomatic balanitis 9
• Only 10-20% of women normally harbor Candida species, so treatment should only occur if symptomatic 5

If Mucopurulent Cervical Discharge Present: Cervicitis

Empiric treatment for both gonorrhea and chlamydia is indicated in high-prevalence populations or if follow-up is uncertain 5

• Treatment should cover Chlamydia trachomatis and Neisseria gonorrhoeae based on local prevalence patterns 5
• Sexual partners must be evaluated and treated 5
• The unexpected bleeding may represent post-coital bleeding from cervicitis 5

Critical Clinical Pitfalls to Avoid

• Do NOT rely on culture for Gardnerella vaginalis as it can be isolated from half of normal women and is not specific for BV 1
• Do NOT diagnose BV without clue cells unless confirmed by Gram stain, as this leads to treating the wrong condition 1
• Do NOT treat male partners for BV despite recurrent symptoms, as controlled studies demonstrate no benefit 8, 9, 1
• Do NOT assume a single diagnosis - mixed infections can occur, and laboratory testing fails to identify a cause in a substantial minority of women 5, 1
• Do NOT overlook PID if the patient has pelvic pain, fever, or cervical motion tenderness, as this requires more aggressive treatment and can lead to serious sequelae including infertility 2

Follow-Up Requirements

• Follow-up is only necessary if symptoms persist or recur after completing treatment 8, 1
• If symptoms persist, repeat evaluation is required to reconsider the diagnosis 6
• Approximately 30% of BV cases recur within 3 months 1
• For trichomoniasis treatment failures, consider metronidazole resistance and consult an expert 5

Special Considerations for Unprotected Sexual Exposure

• The history of unprotected sex mandates STI testing regardless of other findings 5, 2
• Sexual partners should be notified if STIs are diagnosed 5
• Patients should abstain from sexual intercourse until both patient and partners are treated and asymptomatic 5
• Consider HIV and syphilis testing as part of comprehensive STI screening 5