What is the cause and treatment of white discharge in women?

White Vaginal Discharge in Women: Causes and Clinical Significance

White vaginal discharge is often physiologic and beneficial when it represents normal cervical mucus and vaginal secretions, but it becomes pathologic when accompanied by symptoms like itching, odor, or irritation—requiring specific diagnosis and treatment based on the underlying cause. 1

Normal (Beneficial) White Discharge

• Physiologic discharge is protective and maintains vaginal health through lactobacilli that produce lactic acid, hydrogen peroxide, and bacteriocins, creating an acidic environment (pH <4.5) that prevents pathogenic overgrowth. 2

• Normal discharge characteristics include: clear to white color, minimal odor, no associated itching or burning, and pH <4.5. 1, 3

• Approximately 10-20% of healthy women harbor Candida species in the vagina asymptomatically, which is not an indication for treatment. 1

Pathologic White Discharge: Three Main Causes

1. Vulvovaginal Candidiasis (VVC)

Clinical presentation:

• Thick, white "cottage cheese-like" discharge with no odor 1
• Intense pruritus and vulvovaginal erythema 1
• Vaginal soreness, vulvar burning, dyspareunia, and external dysuria 1
• Normal vaginal pH (<4.5) 1

Diagnosis:

• Wet preparation with 10% KOH demonstrating yeasts or pseudohyphae 1
• Culture is not needed for uncomplicated cases but helpful for recurrent infections to identify non-albicans species 1, 4

Treatment for uncomplicated VVC:

• Oral fluconazole 150 mg single dose (most convenient) 1, 5
• Alternative: topical azoles (3-7 day regimens) with 80-90% cure rates 1
• Pregnancy requires 7-day topical azole therapy only—oral fluconazole is contraindicated 1

2. Bacterial Vaginosis (BV)

Clinical presentation:

• Homogeneous, thin, white-gray discharge that smoothly coats vaginal walls 1, 3
• Fishy odor, especially after intercourse or with KOH application (positive whiff test) 1, 3
• pH >4.5 1, 3
• Critical: 50% of women with BV are asymptomatic 2, 6

Diagnosis requires 3 of 4 Amsel criteria:

• Homogeneous white discharge 1
• Clue cells on microscopy 1
• Vaginal pH >4.5 1
• Positive whiff test 1

Treatment:

• Oral metronidazole 500 mg twice daily for 7 days (preferred) 1, 4
• Alternative: intravaginal metronidazole or clindamycin 1, 4
• Do NOT treat male partners—this does not prevent recurrence 1, 6
• High recurrence rate (50-80% within one year) due to failure of lactobacilli recolonization 2

3. Trichomoniasis

Clinical presentation:

• Copious, yellow-green, frothy discharge (not typically white) 1, 3
• Foul or fishy odor 3
• Vulvar irritation 1
• pH >4.5 3

Diagnosis:

• NAAT testing is essential—wet mount sensitivity is only 40-80% 3
• Motile trichomonads on saline wet mount if present 3

Treatment:

• Oral metronidazole or tinidazole 1, 4
• Must treat sexual partners simultaneously 1, 4

Age-Specific Consideration: Elderly Women

• Atrophic vaginitis from postmenopausal estrogen deficiency causes vaginal epithelial thinning, leading to white or tan discharge, friability, and elevated pH (>4.5). 3

• Treatment: vaginal estrogen therapy 3

• Critical pitfall: Any bloody or foul discharge in elderly women requires endometrial biopsy to exclude endometrial cancer. 3

Diagnostic Algorithm

Step 1: Measure vaginal pH

• pH <4.5 → Consider VVC or physiologic discharge 1, 3
• pH >4.5 → Consider BV or trichomoniasis 1, 3

Step 2: Perform whiff test with 10% KOH

• Positive fishy odor → BV or trichomoniasis 1, 3
• Negative → VVC or physiologic 1

Step 3: Microscopy

• Saline wet mount: clue cells (BV), motile trichomonads (trichomoniasis) 1, 3
• KOH preparation: yeast or pseudohyphae (VVC) 1, 3

Step 4: NAAT testing when indicated

• Trichomonas vaginalis (do not rely on wet mount alone) 3
• Neisseria gonorrhoeae and Chlamydia trachomatis if cervicitis suspected 3

Critical Pitfalls to Avoid

• Do not treat asymptomatic Candida colonization—10-20% of women harbor yeast normally. 1

• Do not rely on symptoms alone—clinical presentation overlaps significantly between conditions. 4, 7

• Do not treat male partners for BV—this has consistently failed to prevent recurrence. 1, 6

• Do not use oral fluconazole in pregnancy—only 7-day topical azoles are safe. 1

• Do not miss trichomoniasis by relying only on wet mount—NAAT testing is essential. 3

• Beware of over-the-counter antifungal misuse—women often self-diagnose yeast infections when BV or other conditions are more likely, leading to treatment delays and potential antifungal resistance. 8