How should I evaluate and manage unilateral vulvar pain in a female patient?

Evaluation and Management of Unilateral Vulvar Pain

Begin with a focused physical examination looking for visible lesions, depigmentation, or structural abnormalities, followed by targeted diagnostic testing based on findings, and reserve imaging for palpable masses or when the diagnosis remains unclear after initial evaluation. 1

Initial Clinical Assessment

Key Physical Examination Findings to Identify

• Porcelain-white plaques with fragile atrophic skin in a figure-eight pattern around the vulva and anus suggest lichen sclerosus, particularly in postmenopausal women; look for ecchymosis, purpura, labial fusion, buried clitoris, or introital narrowing 1
• Vulvovaginal erythema with thick white discharge and vaginal pH ≤ 4.5 indicates vulvovaginal candidiasis 1
• Burning pain without visible depigmentation or structural changes characterizes dysesthetic vulvodynia 1
• Tender indurated areas, masses, or abscesses on digital examination may indicate infectious or inflammatory pathology 2

Essential Diagnostic Testing

• Wet-mount with 10% KOH when infectious etiology is suspected to visualize yeast cells or pseudohyphae 1
• Vaginal pH measurement: pH ≤ 4.5 supports candidiasis; pH > 4.5 suggests bacterial vaginosis or alternative diagnoses 1
• Biopsy is mandatory when the diagnosis is uncertain, lesions fail to respond to therapy within 2 months, or there is suspicion of neoplastic transformation 1, 3

Imaging Algorithm

Physical examination remains the primary assessment tool; imaging is reserved for abnormal findings or suspicion of specific pathology. 1, 4

First-Line Imaging (When Indicated)

• Combined transvaginal and transabdominal ultrasound with Doppler is the initial imaging study of choice when a palpable pelvic mass or cyst is identified 1, 4, 2
• Transvaginal ultrasound provides superior spatial and contrast resolution for evaluating the uterus, endometrial canal, fallopian tubes, ovaries, and adnexal masses 4
• Doppler ultrasound evaluates uterine artery blood flow and assesses for pelvic venous disorders, with low-resistance waveforms associated with chronic pelvic pain 4

Problem-Solving Imaging

• MRI pelvis with gadolinium contrast is the problem-solving examination when ultrasound is nondiagnostic or for evaluating pelvic-floor muscular hypertonicity in chronic pelvic pain syndromes 1, 4, 2
• MRI is superior to CT for detecting fistulae and determining disease extent 2

Imaging to Avoid

• CT and plain radiography have no role in the primary evaluation of vulvar pain 1

Treatment Based on Diagnosis

Lichen Sclerosus

• Topical high-potency corticosteroids are first-line therapy 1, 3
• Long-term monitoring is required due to risk of progressive architectural changes and potential malignant transformation (vulvar squamous cell carcinoma) 1, 3
• Regular follow-up is essential to monitor for disease progression and malignancy 1

Vulvovaginal Candidiasis

For non-pregnant patients:

• Single oral dose of fluconazole 150 mg achieves 80-90% cure rates 1
• Alternative topical therapy: Short-course (1-3 days) azole creams provide comparable efficacy—clotrimazole 1% for 7-14 days, miconazole 2% for 7 days, or terconazole 0.8% for 3 days 1

For pregnant patients:

• Only topical azoles for a 7-day course; oral agents are contraindicated 1

For recurrent infection (≥4 episodes per year):

• Initiate a longer induction regimen followed by a 6-month maintenance plan 1
• Evaluate for predisposing factors: diabetes, immunosuppression, HIV, or recent antibiotic use 1

Vulvodynia (Dysesthetic Type)

• Oral medications that decrease nerve hypersensitivity: tricyclic antidepressants, selective serotonin reuptake inhibitors, or anticonvulsants 5
• Pelvic floor biofeedback for pelvic floor dysfunction 5
• Cognitive behavioral therapy 5
• Topical lidocaine for persistent introital pain and dyspareunia 6
• Most women experience substantial improvement when one or more treatments are used 5

Critical Pitfalls to Avoid

• Do not assume depigmentation is benign: Lichen sclerosus carries a risk of malignant transformation; obtain a biopsy if the diagnosis is uncertain or treatment fails 1
• Avoid oral fluconazole in children < 12 years due to insufficient safety data 1
• Prompt biopsy is essential when architectural changes, non-healing lesions, or treatment failure occur 1
• Persistent symptoms beyond 2 months warrant re-evaluation for alternative diagnoses or treatment resistance 1

Special Considerations

• Immunocompromised, diabetic, or elderly patients require heightened suspicion and aggressive approach due to atypical presentations 2
• Pregnancy testing should be considered in women of childbearing age 2
• Assessment of the cervix is suggested in female patients because of the common viral etiology of vulvar, cervical, and anal neoplasms 6