Genital Thrush (Vulvovaginal Candidiasis): Acute & Recurrent Management

Clinical Features & Precipitating Risk Factors

The hallmark symptoms of acute vulvovaginal candidiasis are intense vulval pruritus (itching), burning soreness, dyspareunia (pain during sexual intercourse), and external dysuria. The classic discharge is thick, white, curdy ('cottage cheese-like'), typically without foul odour.

Common precipitating triggers include:

• Broad-Spectrum Antibiotics: Eradicates protective vaginal Lactobacillus species, permitting opportunistic yeast overgrowth.
• High Oestrogen States: Pregnancy, combined oral contraceptive pills, and hormone replacement therapy increase vaginal mucosal glycogen content, feeding yeast proliferation.
• Metabolic Factors: Poorly controlled diabetes mellitus (elevated glycosuria provides a rich metabolic substrate for yeast).
• Immunosuppression: Corticosteroid therapy, chemotherapy, or HIV infection.

Diagnostic Approach: When Over-The-Counter Therapy Fails

Many women with vulval itching misdiagnose themselves with thrush when the underlying pathology is actually dermatitis, contact allergy, bacterial vaginosis, genital herpes, or lichen sclerosus. Over-the-counter azole overuse can induce secondary irritant contact dermatitis.

Clinical evaluation includes a low vaginal swab for microscopy (demonstrating budding yeast cells and pseudohyphae) and fungal culture with species identification and antifungal sensitivities.

Acute Treatment Regimens

For uncomplicated acute episodes, topical and oral azoles demonstrate equivalent clinical cure rates (> 90%):

• Oral Fluconazole: Single oral capsule of 150 mg. (Note: Fluconazole is contraindicated in pregnancy due to potential teratogenic risks with high/prolonged doses).
• Topical Clotrimazole: Intravaginal pessary (e.g. 500 mg single dose or 100 mg for 6 consecutive nights) combined with clotrimazole 1% cream applied to the vulva for external pruritus. Topical clotrimazole is the preferred, safe first-line choice in pregnancy.

Management of Recurrent Vulvovaginal Candidiasis (RVVC)

RVVC is defined as four or more proven episodes within a 12-month period, affecting approximately 5% of women. It is rarely due to drug resistance; rather, it reflects a host immunogenetic susceptibility to Candida antigens.

The Australian and international evidence-based regimen for RVVC employs a two-phase protocol:

1. Induction Phase: Oral Fluconazole 150 mg every 72 hours for 3 doses (Day 1, Day 4, and Day 7) to achieve complete mycological and clinical remission.
2. Maintenance Phase: Oral Fluconazole 150 mg once weekly for 6 months. When maintenance therapy is ceased, approximately 50% remain permanently cured, while others may require extended low-dose suppression.