Lichen sclerosus (LS) is the most commonly misdiagnosed condition in women with recurrent vulvovaginal symptoms — average time to correct diagnosis is 1–2 years. Key clinical distinction: thrush produces white discharge + erythema + satellite lesions on normal skin; LS produces white atrophic skin (figure-of-eight distribution) with fissuring at the posterior fourchette and NO significant discharge. Diagnostic test: thrush improves markedly within 7 days of fluconazole; LS does NOT improve with antifungal but DOES improve with clobetasol propionate 0.05% ointment. LS has 3–5% lifetime SCC risk — annual vulval examination and biopsy of any new lesion required. Ibrexafungerp (Brexafemme — first-in-class glucan synthase inhibitor, MHRA approved) is effective against Candida glabrata and azole-resistant species. Refer to gynaecology/GUM for azole-refractory RVVC rather than continuing ineffective fluconazole.

SGLT2 inhibitor-candida link: dapagliflozin, empagliflozin, canagliflozin cause glycosuria as their therapeutic mechanism → 3–4× increased vulvovaginal candidiasis. Options: (1) Continue SGLT2i + weekly fluconazole 150 mg prophylaxis; (2) Switch antidiabetic if SGLT2i benefit is modest vs thrush burden. Shared decision with patient + diabetes team. Vaginal pH (litmus paper): 5-second test that immediately distinguishes Candida (pH <4.5) from BV (pH >4.5) — the most useful rapid diagnostic step for vaginal symptoms.

Partner reinfection in RVVC: approximately 20% of male partners have asymptomatic candidal colonisation. Reinfection perpetuates the cycle despite prophylaxis. If RVVC not controlled on weekly fluconazole → treat male partner simultaneously (clotrimazole cream BD × 7 days + fluconazole 150 mg stat). Cotton bud vestibular touch test for vulvodynia: gently touch vestibule at 5 and 7 o'clock positions with a moistened cotton bud — pain/allodynia with normal cultures = vulvodynia → vulval clinic referral. Takes 2 minutes and prevents months of inappropriate antifungal treatment.

Vulvodynia affects 8–16% of women but average diagnosis is delayed 5+ years — predominantly because it is repeatedly attributed to thrush. Features that should trigger reconsideration of thrush diagnosis: burning as dominant symptom rather than itch; pain worse with touch/intercourse/clothing rather than with discharge; normal-looking vulva; negative cultures consistently; no response to fluconazole after 7 days. Four or more courses of fluconazole without sustained resolution = vulval examination + cotton bud test + HVS culture + speciation before prescribing again.

Boric acid 600 mg intravaginal pessaries: effective against azole-resistant C. glabrata (70% mycological cure). Unlicensed — specialist compounding pharmacy prescription. OD × 14 days. INTRAVAGINAL ONLY — orally toxic. GUM or gynaecology initiation only. Ibrexafungerp (Brexafemme): first-in-class glucan synthase inhibitor, MHRA approved, effective against C. glabrata. Licensed for acute VVC (300 mg OD × 1 day) and RVVC prevention (300 mg OD × 1 day per month × 6 months). GUM or gynaecology initiation.

Fluconazole weekly suppression: Sobel et al. NEJM 2004 (n=387) — 90% reduction in RVVC episodes, NNT approximately 2. Recurrence ~50% at 6 months after stopping — provide PRN fluconazole 150 mg prescription at course end. Fluconazole in pregnancy: ALL systemic fluconazole should be avoided. MHRA/BNF: avoid in pregnancy. Use topical clotrimazole only. Every woman starting weekly suppression needs effective contraception.

ICS mouth-rinse: reduces oral candidiasis by approximately 90%. Takes 5 seconds to instruct, costs nothing, no side effects. Studies show only 30–40% of ICS users rinse consistently. Ask at every respiratory review. Re-emphasise at every oral thrush diagnosis in an ICS user. Using a spacer with MDI reduces oropharyngeal ICS deposition by ~60% — further reducing oral candidiasis risk.

Vaginal lactic acid probiotics: van de Wijgert et al. 2020 systematic review found statistically significant RVVC reduction with vaginal Lactobacillus preparations vs placebo. Mechanism: lactic acid production by Lactobacillus crispatus/rhamnosus restores acidic pH, inhibiting Candida overgrowth. Balance Activ vaginal gel (lactic acid + glycogen) applied twice weekly as maintenance after antifungal suppression course delays relapse. This microbiome-restoring approach has strong physiological rationale and good OTC availability.

The 2-week treatment failure threshold: fluconazole 150 mg should produce significant improvement within 7 days in confirmed C. albicans VVC. If not, reconsider: non-albicans Candida (culture + speciation), BV (pH test), lichen sclerosus (clobetasol — not antifungal), contact dermatitis (remove causative product), vulvodynia (cotton bud test + normal cultures). Four or more courses of fluconazole without sustained resolution = full diagnostic review before next prescription. Document this process clearly.