Treatment of Positive Pus Cells on Vaginal Swab
For a non-pregnant female with positive pus cells on vaginal swab, empiric treatment should target the three most common causes: bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis, using metronidazole 500mg orally twice daily for 7 days plus either fluconazole 150mg single dose or a topical azole antifungal. 1, 2, 3
Diagnostic Approach Before Treatment
The presence of pus cells (white blood cells) on vaginal swab indicates vaginal inflammation but does not specify the causative organism. 1
Key diagnostic steps include:
- Vaginal pH measurement: pH >4.5 suggests bacterial vaginosis or trichomoniasis; pH ≤4.5 suggests vulvovaginal candidiasis 1, 2
- Wet mount examination: Look for clue cells (bacterial vaginosis), budding yeasts or pseudohyphae (candidiasis), or motile trichomonads (trichomoniasis) 1, 2
- Whiff test: Fishy odor with KOH application indicates bacterial vaginosis 1
- Cultures for N. gonorrhoeae and C. trachomatis: Should be obtained from any site of potential exposure, as these can also cause vaginal inflammation with pus cells 1
Treatment Algorithm
When Specific Diagnosis is Confirmed:
For Bacterial Vaginosis (most common cause at 28%): 4
- Metronidazole 500mg orally twice daily for 7 days 3, 5, 6
- Alternative: Clindamycin vaginal cream 5, 6
- Seven-day regimens provide maximal effectiveness compared to shorter courses 5
For Vulvovaginal Candidiasis:
- Fluconazole 150mg oral tablet as single dose (80-90% cure rate) 2, 7
- Alternative: Short-course topical azoles (clotrimazole 500mg vaginal tablet single application, or miconazole 200mg vaginal suppository for 3 days) 2
- Topical azoles may weaken latex condoms and diaphragms 2
For Trichomoniasis:
- Metronidazole 2g orally as single dose 1, 3
- Alternative: Metronidazole 500mg twice daily for 7 days (preferred for treatment failures) 8
- Sexual partners must be treated simultaneously to prevent reinfection 3, 8
When Specific Diagnosis Cannot Be Determined:
Empiric triple therapy is appropriate when:
- Microscopy is unavailable or negative but symptoms persist 1
- Follow-up cannot be assured 1
- Patient requires immediate treatment 1
Recommended empiric regimen:
- Metronidazole 500mg orally twice daily for 7 days (covers bacterial vaginosis and trichomoniasis) 3, 5
- PLUS Fluconazole 150mg single dose (covers candidiasis) 2, 7
Partner Management
- Bacterial vaginosis: Partner treatment not required, as sexual transmission not proven 5, 6
- Vulvovaginal candidiasis: Partner treatment not recommended unless male partner has symptomatic balanitis 2
- Trichomoniasis: Asymptomatic sexual partners must be treated simultaneously, as this is a sexually transmitted infection 3, 8
Follow-Up Recommendations
- Patients should return only if symptoms persist after completing treatment or recur within 2 months 2
- If symptoms persist despite treatment, reconsider diagnosis and obtain vaginal cultures 2, 8
- Consider alternative diagnoses such as desquamative inflammatory vaginitis, genitourinary syndrome of menopause, or resistant organisms 8
Critical Pitfalls to Avoid
- Do not use shorter courses of metronidazole for bacterial vaginosis: Seven-day regimens are required for maximal effectiveness 5
- Do not rely on negative microscopy alone: 25-40% of genital infections may not be identified by initial testing 1
- Do not forget STI testing: Gonorrhea and chlamydia can present with vaginal discharge and pus cells 1
- Do not treat asymptomatic yeast colonization: 10-20% of women normally harbor Candida without requiring treatment 9
- Ensure treatment completion: Premature discontinuation leads to treatment failure and recurrence 10