How should I evaluate and manage a patient presenting with vaginal pain?

Evaluation and Management of Vaginal Pain

Begin with a thorough physical examination of the perineum, vulva, and vagina, as this is the foundation of clinical evaluation and determines whether imaging is indicated. 1

Initial Clinical Assessment

Key History Elements to Obtain

• Duration of pain: Chronic pain is defined as lasting ≥6 months 1
• Menstrual relationship: Cyclical pain during menstruation suggests endometriosis with rectal involvement 2
• Associated symptoms:
  • Vaginal discharge, odor, itching, dysuria, or dyspareunia suggest infectious vulvovaginitis 3, 4
  • Fever, chills, nausea, vomiting, or foul-smelling discharge indicate more serious conditions requiring urgent evaluation 5
• Sexual history: Obtain privately without parent/guardian present in adolescents to assess for sexually transmitted infections 4
• Positional factors: Pain worsening with prolonged standing suggests pelvic congestion syndrome rather than pelvic inflammatory disease 2

Physical Examination Findings

• Inflammatory signs (erythema, edema): Positive likelihood ratio 2.1-8.4 for candidiasis 6
• "High cheese" odor: Positive likelihood ratio 3.2 for bacterial vaginosis 6
• Absence of odor: Positive likelihood ratio 2.9 for candidiasis 6
• Palpable masses or cysts: Warrant imaging evaluation 1
• Cervical motion tenderness or uterine/adnexal tenderness: Empiric treatment for pelvic inflammatory disease is indicated 1

Office Laboratory Tests

Microscopy of vaginal discharge is the most useful diagnostic tool and should include: 6

• Saline wet mount: Identifies trichomonads and clue cells
• Potassium hydroxide (KOH) preparation: Reveals fungal elements
• Vaginal pH testing: pH >4.5 suggests bacterial vaginosis or trichomoniasis 3
• Whiff test: Fishy odor with KOH indicates bacterial vaginosis 3

Important caveat: Symptoms alone cannot reliably distinguish between causes of vaginitis—absence of itching makes candidiasis less likely (LR 0.18-0.79), and absence of perceived odor makes bacterial vaginosis unlikely (LR 0.07). 6

Imaging Recommendations

When Physical Examination is Abnormal

Ultrasound (transvaginal combined with transabdominal) is the initial imaging modality of choice for evaluating vaginal, vulvar, or perineal pathology when physical examination reveals abnormalities. 1

• Translabial or transvaginal ultrasound: Appropriate for evaluating palpable perineal and vaginal cysts 1
• Doppler ultrasound: Should be performed as a standard component to distinguish cysts from soft tissue 1

When Physical Examination is Normal

Imaging is generally not indicated when the physical examination is normal, as there is no evidence supporting its use in this context. 1

Advanced Imaging Indications

MRI pelvis with gadolinium contrast is appropriate for:

• Problem-solving when ultrasound identifies a cyst or mass requiring further characterization 1
• Suspected deep endometriosis causing rectal pain during menstruation (90.3% sensitivity, 91% specificity) 2
• Pelvic floor muscular hypertonicity in chronic pelvic pain syndromes 1
• Surgical planning when enhancing soft-tissue components suggest infection or neoplasia 1

CT imaging has no role in the primary evaluation of vaginal pain. 1

Management Based on Diagnosis

Infectious Causes (Most Common)

Bacterial Vaginosis:

• Metronidazole is the primary treatment 3

Vulvovaginal Candidiasis:

• Topical antifungal agents are first-line 3
• Fluconazole 150 mg PO single dose achieves 55% therapeutic cure rate, comparable to 7-day intravaginal products 7
• For recurrent vaginitis (≥4 episodes/12 months), single-dose fluconazole achieves only 40% therapeutic cure 7

Trichomoniasis:

• Metronidazole is the primary treatment 3

Pelvic Inflammatory Disease

Empiric treatment should be initiated when minimum criteria are present (cervical motion tenderness OR uterine/adnexal tenderness) in sexually active women at risk for STDs, even before culture results are available. 1

Recommended regimen:

• Ceftriaxone 250 mg IM single dose PLUS Doxycycline 100 mg PO twice daily for 10 days 1

Non-Infectious Causes

• Vaginal atrophy, vaginismus, vulvodynia: Require specialized gynecologic management 1
• Foreign body: Remove if identified 4
• Chemical irritants: Counsel on avoidance of douching and irritants 4

Critical Red Flags Requiring Urgent Evaluation

• Postmenopausal women with vaginal bleeding or suspected adnexal mass: These take precedence over pain evaluation due to risk of endometrial or ovarian neoplasia 1
• Abdominal pain with fever, chills, nausea, vomiting: Consider pelvic inflammatory disease, tubo-ovarian abscess, or other acute pathology 1, 5
• Acute onset severe pain: Requires evaluation for ovarian torsion or ruptured ectopic pregnancy 1

Common pitfall: Tests from self-obtained vaginal swabs and history alone cannot adequately diagnose bacterial vaginosis, trichomoniasis, or candidiasis—the speculum examination remains essential and cost benefits from eliminating it may be negated by long-term costs of mistreatment. 8