What could be causing a slime-like vaginal discharge and how can it be treated?

Slime-Like Vaginal Discharge: Diagnosis and Treatment

Most Likely Diagnosis

Slime-like vaginal discharge is most commonly caused by bacterial vaginosis (BV), which accounts for 40-50% of cases when a pathogen is identified and presents as homogeneous, thin, white-gray discharge. 1, 2

Diagnostic Approach

Essential Office Testing

Perform the following tests to establish the diagnosis:

• Measure vaginal pH using narrow-range pH paper: pH >4.5 suggests BV or trichomoniasis, while pH <4.5 suggests candidiasis 1, 3
• Perform whiff test with 10% KOH: a positive fishy odor indicates BV 1, 3
• Prepare saline wet mount to examine for clue cells (pathognomonic for BV) and assess for inflammatory cells 1, 3
• Prepare KOH mount to examine for yeast or pseudohyphae if candidiasis is suspected 1, 3

Clinical Criteria for BV (Amsel Criteria)

Diagnose BV when three of the following four criteria are present: 1

• Homogeneous, white, non-inflammatory discharge
• Presence of "clue cells" on microscopy
• Vaginal pH greater than 4.5
• Positive whiff test (fishy odor with KOH)

Rule Out Sexually Transmitted Infections

• Obtain nucleic acid amplification testing (NAAT) for Neisseria gonorrhoeae and Chlamydia trachomatis from vaginal swab 1
• Perform NAAT testing for Trichomonas vaginalis due to low sensitivity of wet mount microscopy (only 15-20% of vaginitis cases) 1, 2
• Rule out upper tract infection by checking for costovertebral angle tenderness, dysuria, or fever 1

Treatment Based on Diagnosis

Bacterial Vaginosis (Most Likely)

Treat with metronidazole 500 mg orally twice daily for 7 days as the primary regimen 1, 3

Alternative regimens include:

• Metronidazole gel 0.75% intravaginally 1
• Clindamycin cream 2% intravaginally 1

Important: Partner treatment is NOT required for BV, as it is not sexually transmitted 1, 4

Vulvovaginal Candidiasis (If Confirmed)

If microscopy reveals yeast or pseudohyphae with pH <4.5 and thick, white "cottage cheese-like" discharge:

• Fluconazole 150 mg orally as a single dose achieves 55% therapeutic cure rate 5
• Alternative: Topical azole formulations (butoconazole, clotrimazole) 1
• Note: Only topical azoles should be used during pregnancy 1, 5

Trichomoniasis (If Confirmed)

If NAAT confirms T. vaginalis:

• Metronidazole 2g orally as a single dose 1
• Critical: Sexual partner must be treated simultaneously with the same regimen to prevent reinfection 1

Common Pitfalls to Avoid

• Do not assume all vaginal discharge requires sexual transmission—BV and candidiasis are NOT sexually transmitted diseases 3
• Avoid empirical treatment without proper diagnosis, as women commonly self-diagnose yeast infections when BV or no pathogen is actually present 6
• Do not overlook non-infectious causes such as chemical irritation from soap, which can present with vulvar inflammation and minimal discharge without actual pathogens 7
• Discontinue irritants and avoid douching—regular soap can cause mechanical and chemical irritation mimicking infection 7
• Remember that up to 50% of women with BV may be asymptomatic, so the presence of discharge alone warrants evaluation 3

Special Considerations

• In postmenopausal women, consider atrophic vaginitis from estrogen deficiency, which causes vaginal epithelial thinning and increased susceptibility to infection 3
• During pregnancy, BV is associated with adverse pregnancy outcomes and should be treated with metronidazole 1
• BV has a high recurrence rate, and treatment before surgical procedures such as abortion or hysterectomy is recommended 1