What is the appropriate workup and treatment for a patient presenting with pruritus vulvae (itchy vulva)?

Workup for Itchy Vulva

Begin with microscopic examination using wet-mount preparation with 10% KOH to visualize yeast or pseudohyphae, measure vaginal pH, and obtain vaginal cultures if microscopy is negative—vulvovaginal candidiasis is the most common infectious cause, but you must rule out other dermatologic conditions through careful visual inspection for characteristic findings. 1

Initial Diagnostic Steps

History and Physical Examination

• Obtain detailed symptom characterization: duration, severity, associated discharge, dyspareunia, external dysuria, and previous treatments including over-the-counter antifungal use 1, 2
• Assess for risk factors: recent antibiotic use, diabetes, immunosuppression (HIV, corticosteroids), pregnancy status, and sexual activity 1
• Examine the entire vulva, vagina, and cervix: look specifically for erythema, edema, satellite lesions, discharge characteristics, and any structural changes 1, 3

Laboratory Testing

• Perform wet-mount microscopy with 10% KOH: this visualizes yeast, pseudohyphae, or hyphae in vulvovaginal candidiasis 1
• Measure vaginal pH: normal pH ≤4.5 suggests candidiasis, while elevated pH (>4.5) indicates bacterial vaginosis or trichomoniasis 1
• Obtain vaginal culture: this is the gold standard for diagnosis, especially when microscopy is negative or symptoms persist despite treatment 1
• Screen for sexually transmitted infections: consider testing based on risk factors and clinical presentation 3

Key Differential Diagnoses to Consider

Vulvovaginal Candidiasis (Most Common Infectious Cause)

• Classic presentation: vulvar and vaginal itching (most specific symptom), erythema, edema, white cottage cheese-like discharge, external dysuria, and dyspareunia 1
• Affects 70-75% of women during their lifetime and represents the second most common cause of vaginal infections 1

Lichen Sclerosus (Most Important Non-Infectious Cause)

• Characteristic findings: porcelain-white plaques, fragile atrophic skin, fissures in figure-eight pattern around vulva and anus, intractable pruritus, and architectural changes (labial fusion, buried clitoris, introital narrowing) 4
• Occurs most commonly in postmenopausal women and requires biopsy if diagnosis is uncertain or disease fails to respond to treatment 4
• Critical consideration: patients are at risk for vulvar squamous cell carcinoma and require close monitoring 5

Other Dermatologic Conditions

• Lichen planus: inflammatory autoimmune disorder with potential for significant scarring if untreated 5
• Lichen simplex chronicus: persistent itch-scratch cycle leading to thickened epithelium 5
• Contact dermatitis/eczema: often multifactorial with environmental irritants 3, 5
• Vulvodynia: diagnosis of exclusion characterized by vulvar pain without visible findings 4, 5

When to Perform Biopsy

Obtain vulvar biopsy if: diagnosis is uncertain, depigmentation or architectural changes are present, disease fails to respond to treatment within 2-3 months, or there is any suspicion of neoplastic change 4, 3

Common Pitfalls to Avoid

• Do not treat empirically without microscopic confirmation: self-diagnosis as "thrush" is common but unreliable, and inappropriate over-the-counter antifungal use can cause further irritation 1, 2
• Do not assume single etiology: multiple conditions can coexist simultaneously (e.g., candidiasis with bacterial vaginosis, or candidiasis with underlying dermatologic condition) 6, 7, 2
• Do not overlook non-infectious causes: if symptoms persist after appropriate antifungal treatment or microscopy is negative, consider dermatologic conditions like lichen sclerosus, lichen planus, or contact dermatitis 4, 3, 5
• Do not miss concurrent sexually transmitted infections: vulvovaginal candidiasis can occur concomitantly with STIs, requiring appropriate testing 6, 3

Follow-Up Recommendations

• Instruct patients to return if: symptoms persist after completing treatment, symptoms recur within 2 months, or new symptoms develop 1
• Consider resistant organisms or alternative diagnoses: if symptoms persist despite appropriate treatment, obtain cultures to identify non-albicans species and reassess for dermatologic conditions 1
• For recurrent symptoms (≥4 episodes/year): obtain cultures to confirm diagnosis and identify species, as this affects treatment approach 1