What is the cause and treatment for a yellowish-white, itchy, and smelly vaginal discharge?

Treatment for White Smelly Discharge with Yellow Tinge and Itching

Based on your symptoms of yellowish-white, smelly discharge with itching, you likely have bacterial vaginosis (BV) or trichomoniasis, which should be treated with metronidazole 500mg orally twice daily for 7 days. 1

Diagnostic Considerations

To properly identify the cause of your symptoms, consider these key characteristics:

Bacterial Vaginosis (BV)

• Discharge: Homogeneous, white, thin discharge that adheres to vaginal walls
• Odor: Fishy or musty smell, especially after sex or when mixed with KOH ("whiff test")
• pH: Greater than 4.5
• Microscopy: Presence of "clue cells"
• Symptoms: Discharge and odor, sometimes mild irritation 2, 1

Trichomoniasis

• Discharge: Yellow-green, sometimes frothy discharge
• Odor: Malodorous
• pH: Greater than 4.5
• Microscopy: Motile trichomonads visible
• Symptoms: Discharge, odor, possible vulvar irritation 2

Vulvovaginal Candidiasis (VVC)

• Discharge: White, thick, "cottage cheese-like"
• Odor: Minimal or none
• pH: Normal (≤4.5)
• Microscopy: Yeast or pseudohyphae visible with KOH prep
• Symptoms: Intense itching and vulvar pain 1, 3

Treatment Recommendations

For Bacterial Vaginosis:

• First-line treatment: Metronidazole 500mg orally twice daily for 7 days (95% cure rate) 1
• Alternative options:
  • Metronidazole gel 0.75% intravaginally once daily for 5 days
  • Clindamycin cream 2% intravaginally at bedtime for 7 days
  • Metronidazole 2g orally in a single dose (lower efficacy at 84%) 2, 1

For Trichomoniasis:

• Recommended regimen: Metronidazole 2g orally in a single dose 2
• Alternative regimen: Metronidazole 500mg twice daily for 7 days 2

For Vulvovaginal Candidiasis:

• Topical options:
  • Clotrimazole 1% cream for 7-14 days
  • Miconazole 2% cream for 7 days
  • Various other azole preparations 1, 4
• Oral option: Fluconazole 150mg as a single dose 1

Follow-Up Considerations

• If symptoms persist after treatment, return for re-evaluation as you may need different treatment or have multiple infections 1
• Treatment of sexual partners is recommended for trichomoniasis but not typically for BV or candidiasis 2, 1
• For recurrent BV (common in 30% of women), consider extended treatment with metronidazole 500mg twice daily for 10-14 days 1

Prevention Tips

• Consider consistent condom use during sexual intercourse, which may help prevent recurrence of BV 1
• Avoid douching and irritating feminine hygiene products 1
• If you're experiencing recurrent infections, follow-up with your healthcare provider for additional testing and management 1

The combination of yellowish-white discharge with odor and itching strongly suggests either BV or trichomoniasis, with BV being the most common cause of vaginal discharge (40-50% of cases) 3. Proper diagnosis through microscopic examination and pH testing is ideal, but based on your symptoms, treatment with metronidazole is the most appropriate first step.