What is the likely cause and appropriate initial management for a 52‑year‑old woman with burning on urination confined to the external genitalia, normal urinalysis and no odor?

External Burning with Urination and Normal Urinalysis

This 52-year-old woman most likely has vulvovaginal candidiasis causing external dysuria from urine contact with inflamed vulvar skin, and should be treated with either a single 150 mg oral dose of fluconazole or a 7-day course of topical azole therapy.

Most Likely Diagnosis

The key clinical features point strongly toward vulvovaginal candidiasis:

• External-only burning (not internal) indicates that urine is contacting inflamed vulvar skin rather than an inflamed urethra or bladder 1
• Normal urinalysis excludes urinary tract infection and confirms the symptoms originate from external genital tissue 1
• Absence of odor makes bacterial vaginosis and trichomoniasis highly unlikely, as both characteristically produce malodorous discharge 2, 3
• Age 52 years places her in the perimenopausal/postmenopausal range where vulvovaginal candidiasis remains common, affecting up to 75% of women at least once in their lifetime 1

The pattern of external dysuria occurs when urine contacts inflamed vulvar skin in vulvovaginal candidiasis, creating a burning sensation that patients often describe as "on the outside" rather than "inside" 1.

Diagnostic Confirmation Before Treatment

Do not treat empirically without microscopic confirmation, as self-diagnosis is accurate in only 30-50% of cases 1:

• Perform wet-mount microscopy with 10% KOH to visualize budding yeast or pseudohyphae 1, 3
• Measure vaginal pH with narrow-range pH paper: pH ≤4.5 supports candidiasis, while pH >4.5 suggests bacterial vaginosis or trichomoniasis 1, 2
• Obtain vaginal culture if microscopy is negative but clinical suspicion remains high, or if symptoms recur after treatment 1
• Inspect the vulva and vaginal opening for erythema, edema, excoriation, or fissures—hallmark features of vulvovaginal candidiasis 1

First-Line Treatment Options

Both oral and topical regimens achieve cure rates exceeding 90% for uncomplicated infection 1:

Oral Therapy

• Fluconazole 150 mg as a single oral dose is the most convenient option 1, 3

Topical Azole Therapy (7-day regimens)

• Clotrimazole 1% cream 5 g intravaginally daily for 7 days 1
• Miconazole 2% cream 5 g intravaginally daily for 7 days 1
• Terconazole 0.4% cream 5 g intravaginally daily for 7 days 1

If severe vulvar inflammation is present (marked erythema, edema, excoriation, or fissures), extend topical azole therapy to 7-14 days rather than using a single oral dose 1.

Symptomatic Relief Measures

• Apply vaginal moisturizers 3-5 times per week to the vagina, introitus, and external vulvar folds to alleviate dryness 1
• Use water-based lubricants during sexual activity 1
• Consider topical lidocaine for persistent introital pain 1

When to Consider Alternative Diagnoses

If symptoms persist after appropriate treatment or microscopy is negative, consider:

Lichen Sclerosus

• Look for porcelain-white plaques, fragile atrophic skin, and fissures in a figure-eight pattern around vulva and anus 4, 5
• Most common in postmenopausal women (85-98% affect anogenital area) 4
• Characterized by intractable pruritus, vulvar soreness, dyspareunia, and architectural changes including labial fusion or buried clitoris 4, 5
• Biopsy is mandatory if diagnosis is uncertain or disease fails to respond to treatment 4

Vulvodynia/Dysesthetic Vulvodynia

• Chronic vulvar pain described as burning, stinging, irritation, or rawness without visible depigmentation or structural changes 4, 6
• Diagnosis of exclusion with unknown etiology 6
• Does not respond to topical corticosteroids; requires neuropathic pain management 5

Atrophic Vaginitis

• Common in postmenopausal women due to estrogen deficiency 3
• Presents with vaginal dryness, dyspareunia, and burning 3
• Treated with hormonal and nonhormonal therapies 3

Management of Recurrent Symptoms

If the patient experiences ≥3 episodes within 12 months, she meets criteria for recurrent vulvovaginal candidiasis and requires a two-phase approach 1:

Induction Phase

• 10-14 days of topical azole or oral fluconazole to achieve remission 1

Maintenance Phase

• Fluconazole 150 mg orally once weekly for 6 months 1
• This suppressive regimen controls symptoms in >90% of patients during treatment 1
• After stopping maintenance therapy, anticipate a 40-50% recurrence rate 1

For persistent symptoms despite appropriate azole therapy, obtain vaginal culture to detect non-albicans Candida species (especially C. glabrata), which require alternative treatment with boric acid 600 mg intravaginally daily for 14 days 1.

Critical Pitfalls to Avoid

• Do not assume all external burning is a UTI—normal urinalysis excludes bladder/urethral infection 1
• Do not treat without microscopic confirmation—clinical symptoms overlap significantly with bacterial vaginosis, trichomoniasis, and non-infectious causes 1, 3
• Do not use short-course (1-3 day) regimens if severe vulvar inflammation is present; these cases require 7-14 day therapy 1
• Do not treat asymptomatic Candida colonization, present in 10-20% of women 1
• Do not routinely treat sexual partners, as vulvovaginal candidiasis is not a sexually transmitted infection 1

Follow-Up Recommendations

• Patients should seek further evaluation if symptoms persist after completing therapy or recur within 2 months 1
• If ≥3 episodes occur within 12 months, initiate the two-phase recurrent vulvovaginal candidiasis protocol 1