How to approach a female patient presenting with leukorrhea (white vaginal discharge)?

Approach to Whitish Vaginal Discharge

Perform a pelvic examination with pH testing and microscopic evaluation of the discharge to differentiate between the three most common causes: bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis, as these require different treatments. 1, 2

Initial Diagnostic Steps

Physical Examination

• Examine the discharge characteristics directly: homogeneous white discharge coating vaginal walls suggests bacterial vaginosis (BV), while thick white "cottage cheese" discharge indicates candidiasis 1
• Assess for vulvar inflammation: presence of erythema, pruritus, and minimal discharge without vaginal pathogens suggests mechanical or chemical irritation rather than infection 1
• Check cervical appearance: mucopurulent cervical discharge or cervical motion tenderness may indicate cervicitis or pelvic inflammatory disease requiring different management 1

Laboratory Testing (Performed at Point-of-Care)

• Measure vaginal pH using narrow-range pH paper: pH >4.5 indicates BV or trichomoniasis, while pH ≤4.5 suggests candidiasis 1, 2
• Prepare two microscope slides: dilute discharge sample in 1-2 drops of 0.9% normal saline on one slide and 10% KOH on a second slide 1
• Perform whiff test: fishy amine odor immediately after applying KOH indicates BV or trichomoniasis 1
• Examine saline wet mount: look for motile trichomonads or clue cells (epithelial cells with adherent bacteria) characteristic of BV 1
• Examine KOH preparation: identify yeast or pseudohyphae of Candida species 1

Diagnosis and Treatment by Etiology

Bacterial Vaginosis (Most Common Cause)

Clinical criteria require 3 of 4 findings:

• Homogeneous white noninflammatory discharge adhering to vaginal walls 1
• Clue cells on microscopy 1
• Vaginal pH >4.5 1
• Positive whiff test 1

Treatment (only if symptomatic):

• Metronidazole 500 mg orally twice daily for 7 days 1
• Advise patients to avoid alcohol during and for 2 days after metronidazole treatment 1
• Do not treat male partners as this does not prevent recurrence 1, 2

Vulvovaginal Candidiasis

Clinical presentation:

• Pruritus, vulvar erythema, soreness, and thick white discharge 1, 2
• Normal vaginal pH (≤4.5) 2
• Yeast or pseudohyphae visible on KOH preparation 1

Treatment options for uncomplicated cases:

• Oral: Fluconazole 150 mg single dose 1, 3
• Topical (3-day regimens): Clotrimazole 100 mg vaginal tablet twice daily, Miconazole 200 mg suppository daily, or Terconazole 0.8% cream 5g daily 1
• Single-dose topical: Clotrimazole 500 mg vaginal tablet or Tioconazole 6.5% ointment 5g 1

For recurrent candidiasis (≥4 episodes/year):

• Initial treatment with 7-14 day course followed by maintenance therapy with fluconazole 150 mg weekly for 6 months 2

Trichomoniasis

Clinical presentation:

• Yellow-green frothy discharge with malodor 2
• Vaginal pH >4.5 1
• Motile trichomonads on saline wet mount 1

Treatment:

• Metronidazole (specific dosing per CDC guidelines) 1
• Treat sexual partners as this is sexually transmitted 2

Critical Pitfalls to Avoid

• Do not rely on symptoms alone: discharge characteristics overlap significantly between conditions, requiring laboratory confirmation 1, 4
• Do not treat asymptomatic candidal colonization: present in 10-20% of healthy women and does not require treatment 1, 2
• Do not recommend self-treatment unless the patient has been previously diagnosed with candidiasis by a physician and has identical symptoms 1, 2
• Do not miss cervicitis or PID: if cervical motion tenderness, uterine tenderness, or mucopurulent cervical discharge is present, consider upper tract infection requiring broader antibiotic coverage 1, 5
• Avoid vaginal douching: disrupts normal lactobacilli flora and increases infection risk 2

When to Consider Alternative Diagnoses

• If microscopy is negative but symptoms persist: consider culture for Candida or Trichomonas (more sensitive than microscopy) or non-infectious causes 1
• If patient has new or multiple sexual partners: test for Chlamydia trachomatis and Neisseria gonorrhoeae even without typical cervicitis findings 5, 6
• If vulvar symptoms predominate with minimal discharge: consider vulvar dermatoses, allergic reactions, or irritant contact dermatitis 1, 6

Special Populations

• Pregnant women: use only 7-day topical antifungal treatments for candidiasis; oral fluconazole should be avoided 2
• Recurrent infections in same patient: consider underlying conditions such as diabetes, immunosuppression, or HIV infection 1, 2

Follow-Up

• Patients should return only if symptoms persist or recur within 2 months 1, 2
• Laboratory testing failure to identify a cause occurs in a substantial minority of women, requiring clinical reassessment 1