Treatment of Vaginal Discharge with Fishy Odor and Itch

Diagnostic Confirmation

The Centers for Disease Control and Prevention (CDC) recommends measuring vaginal pH using narrow-range pH paper to confirm the diagnosis, as bacterial vaginosis (BV) typically shows pH >4.5, while candidiasis shows pH ≤4.5 3, 4, 2
The CDC suggests performing the whiff test by adding 10% KOH to vaginal discharge to identify a fishy amine odor, which indicates BV 3, 4, 5
The American College of Obstetricians and Gynecologists (ACOG) recommends examining wet mount microscopy with saline preparation to identify clue cells diagnostic of BV, and KOH preparation to identify yeast or pseudohyphae indicating candidiasis 3, 4, 2
The CDC recommends looking for clinical signs, such as homogeneous white-grey discharge coating vaginal walls in BV, and vulvar erythema, edema, and thick white "cottage cheese" discharge in candidiasis 3

The CDC recommends metronidazole 500 mg orally twice daily for 7 days as the first-line treatment for bacterial vaginosis 1, 2
The CDC suggests fluconazole 150 mg as a single oral dose for the treatment of vulvovaginal candidiasis, with 55% therapeutic cure rates 2

The CDC advises patients to avoid all alcohol during metronidazole treatment and for 24 hours after completion to prevent disulfiram-like reactions 1
The CDC recommends completing the full 7-day metronidazole course to reduce recurrence risk, even if symptoms resolve early 1

The American Academy of Pediatrics (AAP) recommends reconsidering trichomoniasis if symptoms persist after treatment, as it can cause fishy odor and elevated pH, and wet mount microscopy may miss it 30-50% of the time 5
The CDC suggests evaluating for mixed infections if laboratory testing fails to identify a cause, as a substantial minority of women with vaginal complaints may have mixed infections 3, 6

The CDC recommends no routine follow-up if symptoms completely resolve after treatment 1, 2
The CDC suggests returning for persistent or recurrent symptoms within 2 months, which may indicate treatment failure or reinfection requiring extended therapy or alternative agents 1, 2

The CDC advises against treating based on symptoms alone and recommends confirming the diagnosis with pH and microscopy 3
The CDC recommends against using metronidazole as a single 2-gram dose for BV, as it requires a 7-day course for optimal cure rates 1
The CDC advises against treating male partners for BV, as partner treatment does not reduce recurrence rates and is not recommended 3, 4, 1
The CDC recommends avoiding empiric treatment without considering pregnancy status, as pregnant women with BV require treatment due to associations with preterm birth 1