TOPIC 47: Vaginal Discharge – Understand the Differential Diagnosis, Evaluation, and Management of Vaginal Discharge in an Adolescent

MOCA-PBR – 2025 Edition TOPIC 47: Vaginal Discharge – Understand the Differential Diagnosis, Evaluation, and Management of Vaginal Discharge in an Adolescent

OFFICIAL ABP TOPIC:

Understand the differential diagnosis, evaluation, and management of vaginal discharge in an adolescent

BACKGROUND

Vaginal discharge is a common presenting symptom in adolescents. While some discharge is a normal physiologic response (leukorrhea), pediatricians should be able to differentiate normal discharge from pathologic etiologies and treat them appropriately.

DIFFERENTIAL DIAGNOSIS OF VAGINAL DISCHARGE

Causes of vaginal discharge include the following:

  • Physiologic Leukorrhea: Thin, white, odorless discharge (typically 1-4 mL/day); no associated symptoms; normal pH (4.0–4.5); negative workup.
  • Bacterial Vaginosis (BV): Malodorous, thin gray discharge; pH >4.5; clue cells and positive whiff test.
  • Candidiasis: Thick, white cottage cheese-like discharge; vulvovaginal pruritus and erythema; normal pH (4.0–4.5); budding yeast and hyphae on microscopy.
  • Trichomoniasis: Copious yellow-green frothy discharge; associated pruritus and dysuria; pH >4.5; motile trichomonads; positive nucleic acid amplification test (NAAT).
  • Cervicitis (Gonorrhea/Chlamydia): Purulent endocervical discharge; friable cervix; positive NAAT.
  • Pelvic Inflammatory Disease: Purulent endocervical discharge; fever; intermenstrual bleeding; lower abdominal or pelvic pain; cervical motion, uterine, or adnexal tenderness.
  • Foreign Body: Persistent, malodorous discharge; requires visualization and removal.
  • Non-Infectious Causes: Variable discharge characteristics; negative infectious workup; irritants (vaginal washes or douches) or dermatologic conditions suspected. Cervical cancer is rare in adolescents.

EVALUATION OF VAGINAL DISCHARGE

HISTORY

  • Discharge Characteristics: Quantity, color, consistency, odor.
  • Associated Symptoms: Pruritus, burning, dysuria, dyspareunia, abdominal pain.
  • Sexual History: New/multiple partners, specific practices, STI history, contraception.
  • Medical Conditions: Diabetes, immunosuppression.
  • Medications: Recent antibiotics.
  • Hygiene Practices: Douching, tight clothing, scented products.

PHYSICAL EXAM

  • Vulva: Check for erythema, edema, excoriations (e.g., candidiasis, trichomoniasis).
  • Speculum exam of vagina and cervix: Assess for inflammation, lesions, discharge characteristics, and cervical motion tenderness.
  • Bimanual exam of the pelvis: Evaluate for masses, uterine or adnexal tenderness.

Any sexually active adolescent with pelvic or lower abdominal pain, vaginal discharge, and cervical, uterine, or adnexal tenderness on exam should receive a diagnosis of pelvic inflammatory disease (PID) and presumptive treatment because of the risk of long-term complications if treatment is delayed.

DIAGNOSTIC TESTING

Bacterial vaginosis, candidiasis, and trichomoniasis are the most common causes of abnormal vaginal discharge and account for 70% of cases. Diagnosis should not be based on discharge appearance alone. A stepwise approach to testing is outlined below:

  1. NAAT for gonorrhea and chlamydia in all sexually active patients.
  2. pH and microscopy:
    • Vaginal pH >4.5: Suggests BV or trichomoniasis.
    • Microscopy:
      • Saline wet mount: Motile trichomonads (trichomoniasis), clue cells (BV).
      • KOH wet mount: Candida budding yeast and hyphae.
  3. If microscopy results are nondiagnostic or laboratory testing is preferred:
    • Send NAAT for BV, candidiasis, and trichomoniasis.
    • Consider culture for recurrent or resistant candidiasis (culture not useful for BV).

HISTORYDISTINGUISHING CHARACTERISTICS FOR COMMON ETIOLOGIES OF VAGINAL DISCHARGE

CONDITION 

SYMPTOMS 

DISCHARGE 

OTHER FINDINGS 

PH 

DIAGNOSTIC TESTS 

Normal discharge

None

Thin, white

Squamous epithelial cells, lactobacilli, rare WBCs, negative whiff test

4-4.5

Microscopy

Bacterial vaginosis

Minimal irritation

Thin, gray, fishy smell

Clue cells, positive whiff test

>4.5

Microscopy, NAAT

Candidiasis

Pruritus, soreness, dyspareunia

Thick, white “cottage cheese”

Budding yeast or hyphae on KOH prep

4.0–4.5

KOH prep, NAAT, culture

Trichomoniasis

Pruritus, dysuria, dyspareunia

Green-yellow, frothy

Motile trichomonads on wet mount, whiff test often positive

5-6

Microscopy, NAAT

Vaginitis due to chlamydia/ gonorrhea

Mucopurulent discharge, spotting

Purulent

Cervical friability, erythema

Varies

NAAT for gonorrhea or chlamydia

MANAGEMENT OF VAGINITIS

CONDITION 

FIRST-LINE TREATMENT 

ALTERNATIVE TREATMENT 

DURATION 

SPECIAL CONSIDERATIONS 

BV

Metronidazole 500 mg PO BID

Clindamycin cream 2% intravaginally

7 days

Avoid alcohol during metronidazole use

Candidiasis

Fluconazole 150 mg PO x 1 dose

Topical azoles (clotrimazole, miconazole)

1–3 days (uncomplicated)

Use longer courses for complicated cases

Trichomoniasis

Metronidazole 2 g PO x 1 dose

Tinidazole 2 g PO x 1 dose

Single dose

Treat sexual partners; avoid alcohol

Gonorrhea

Ceftriaxone 500 mg IM single dose

If allergic: Gentamicin + Azithromycin

Single dose

Treat for chlamydia if co-infection not excluded

Chlamydia

Doxycycline 100 mg BID

Azithromycin 1 g single dose PO

7 days (doxycycline)

Avoid doxycycline in pregnancy

Non-Infectious

Remove irritants

N/A

N/A

Focus on addressing underlying cause

With trichomoniasis, gonorrhea, and chlamydia, treating sexual partners is crucial to prevent reinfection. Consider expedited partner therapy when appropriate.

Adolescents with vaginitis usually should not receive treatment based on symptoms alone. However, a presumptive diagnosis of PID (pelvic pain + cervical/uterine/adnexal tenderness) should get immediate treatment with a single dose of IM ceftriaxone, plus doxycycline and metronidazole for 14 days. Delaying treatment increases the risk of long-term complications.

REFERENCES

https://www.cdc.gov/std/treatment-guidelines/vaginal-discharge.htm

https://www.uptodate.com/contents/candida-vulvovaginitis-in-adults-treatment-of-acute-infection

https://www.uptodate.com/contents/vaginitis-in-adults-initial-evaluation

https://www.uptodate.com/contents/pelvic-inflammatory-disease-treatment-in-adults-and-adolescents

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