Yeast infection of the vulva/vagina — thick white discharge, intense pruritus, normal pH.
Also known as: yeast infection, candidiasis, vulvovaginal candidiasis, VVC, monilial vaginitis
Overview
Symptomatic vulvar and vaginal inflammation caused by Candida species, most commonly Candida albicans (~85-90%), with C. glabrata, C. krusei, and C. tropicalis accounting for non-albicans cases that are often azole-resistant.
Epidemiology
Affects ~75% of women at least once; ~5-8% experience recurrent vulvovaginal candidiasis (RVVC, ≥3 episodes/year). Second most common cause of vaginitis after BV.
Try two board-style Candidal Vulvovaginitis questions
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Question 1ReproductiveMedium
A 32-year-old woman presents with 3 days of vulvar itching, burning, and thick white discharge. She was started on azithromycin 5 days ago for community-acquired pneumonia and takes quetiapine nightly for bipolar disorder. Pelvic exam reveals erythematous vulva with curd-like discharge; KOH prep shows pseudohyphae and budding yeast. ECG from her last admission showed a QTc of 470 ms. Which of the following is the most appropriate treatment?
AIntravaginal clotrimazole
BOral fluconazole
COral itraconazole
DIntravaginal boric acid
EIntravaginal metronidazole
Reveal answer & full explanation
Correct answer: A — Intravaginal clotrimazole
AIntravaginal clotrimazole✓
BOral fluconazole
COral itraconazole
DIntravaginal boric acid
EIntravaginal metronidazole
Why Intravaginal clotrimazole is correct
This patient has uncomplicated vulvovaginal candidiasis: vulvar itching and burning, curd-like discharge, and a KOH prep showing pseudohyphae and budding yeast
The decisive issue is medication-related QT risk — azithromycin and quetiapine both prolong the QT interval, and her baseline QTc is already borderline-prolonged at 470 ms
Intravaginal azoles (clotrimazole, miconazole, terconazole) are highly effective for uncomplicated candidiasis and have minimal systemic absorption, so they avoid additive QT prolongation
For uncomplicated disease, topical and oral azoles achieve similar clinical cure rates (Cochrane review, Denison 2020), and CDC 2021 lists both routes as recommended, so safety is the tie-breaker and the topical agent is the most appropriate choice
Why the others are wrong
Intravaginal metronidazole — treats bacterial vaginosis (the vaginal gel is not adequate for trichomoniasis, which needs an oral nitroimidazole such as metronidazole or tinidazole) and has no activity against Candida; buzzword-match trap, since 'vaginal discharge' pattern-matches to metronidazole but the KOH pseudohyphae and budding yeast identify yeast, not clue cells or motile trichomonads
Oral itraconazole — a strong CYP3A4 inhibitor that would sharply raise quetiapine levels (the quetiapine label calls for cutting the dose to one-sixth with strong CYP3A4 inhibitors), so its torsades risk here is at least as high as fluconazole's; it is also not a CDC-recommended regimen for vulvovaginal candidiasis; right-diagnosis-wrong-route trap
Oral fluconazole — CDC 2021 does list single-dose fluconazole 150 mg PO as a recommended regimen, but picking it treats azithromycin, quetiapine and the 470 ms QTc as background when they are the decision-changers: fluconazole prolongs QT via IKr (hERG) inhibition and, as a moderate CYP3A4 inhibitor, can raise quetiapine levels, and the US Diflucan label contraindicates coadministration with QT-prolonging drugs metabolized by CYP3A4, a class description quetiapine fits. One dose is low absolute risk on its own, but here it stacks on two QT-prolonging drugs (azithromycin's half-life of about 68 h keeps it on board) and a borderline-prolonged QTc, when an equally recommended topical azole avoids nearly all of that risk; premature-closure trap
Intravaginal boric acid — a vaginal therapy, which makes it tempting given her QT risk, but boric acid is reserved for non-albicans (especially Candida glabrata) or azole-refractory infection; pseudohyphae on KOH point to Candida albicans, and uncomplicated candidiasis is treated first-line with an azole; right-route-wrong-drug trap
Question 2ReproductiveEasy
A 24-year-old woman who is not pregnant has thick, white, 'cottage cheese' vaginal discharge with vulvar pruritus and burning. There is no malodor. A potassium hydroxide (KOH) prep of the discharge shows pseudohyphae and budding yeast. Which of the following is the most appropriate treatment?
AFluconazole 150 mg PO single dose
BFluconazole 150 mg weekly for 6 months
CBoric acid vaginally for 14 days
DFluconazole 150 mg q72h for 3 doses
EMetronidazole 500 mg BID for 7 days
Reveal answer & full explanation
Correct answer: A — Fluconazole 150 mg PO single dose
AFluconazole 150 mg PO single dose✓
BFluconazole 150 mg weekly for 6 months
CBoric acid vaginally for 14 days
DFluconazole 150 mg q72h for 3 doses
EMetronidazole 500 mg BID for 7 days
Why Fluconazole 150 mg PO single dose is correct
Thick, white, curd-like discharge without odor, intense vulvar pruritus, and a KOH prep showing pseudohyphae and budding yeast identify uncomplicated vulvovaginal candidiasis (Candida albicans).
Uncomplicated disease in a non-pregnant patient is treated with a single 150 mg oral dose of fluconazole or a short course of a topical azole, per current CDC STI guidance.
Recurrent disease (3 or more symptomatic episodes in 1 year) is treated with induction followed by weekly fluconazole maintenance.
Why the others are wrong
Fluconazole 150 mg weekly for 6 months — the suppressive regimen for recurrent vulvovaginal candidiasis and only after induction dosing; this woman has a single uncomplicated episode that a one-time 150 mg dose clears. Sets the overtreatment trap.
Metronidazole 500 mg BID for 7 days — treats bacterial vaginosis and trichomoniasis, not candidiasis; the absence of clue cells and odor with the presence of yeast exclude it. Sets the premature-closure trap of defaulting to the most common vaginitis regimen.
Boric acid vaginally for 14 days — reserved for azole-refractory or non-albicans species such as C. glabrata, which do not form pseudohyphae; the KOH findings here are those of C. albicans. Sets the second-line-before-first-line trap.
Fluconazole 150 mg q72h for 3 doses — the every-72-hour sequential course, given as 3 doses for induction in recurrent disease and as 2 or 3 doses for severe vulvovaginitis (extensive erythema, edema, excoriation, or fissures), both forms of complicated infection; this is a single uncomplicated episode that one 150 mg dose treats. Sets the trap of using the complicated-disease regimen for uncomplicated infection.
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Candida is a normal vaginal commensal in ~20% of women. Disruption of microbial balance (e.g., antibiotic-induced loss of Lactobacillus), local immune changes, or substrate availability (hyperglycemia, glucosuria from SGLT2 inhibitors) permits overgrowth and hyphal invasion of vaginal epithelium, producing inflammation.
Prefer a topical azole when oral fluconazole poses QT-prolongation or drug-interaction risk (e.g., other QT-prolonging drugs, warfarin, CYP3A4 substrates)
Severe disease: fluconazole 150 mg PO × 2 doses 72 hours apart, OR topical azole × 7-14 days
Recurrent (≥3 episodes/year): induction with fluconazole 150 mg q72h × 3 doses, then suppression with fluconazole 150 mg weekly × 6 months
Non-albicans (especially C. glabrata): 7-14 days of a non-fluconazole azole (oral or topical) first; if it recurs, boric acid 600 mg vaginal capsule daily × 3 weeks (CDC 2021; IDSA uses 14 days for azole-refractory C. glabrata); boric acid is toxic if swallowed
Ibrexafungerp (oral triterpenoid) is FDA-approved for VVC treatment and for reducing RVVC recurrence, but it is not among the CDC 2021 regimens and is contraindicated in pregnancy (boxed warning for embryo-fetal toxicity)
Pregnancy
Topical azoles only (clotrimazole, miconazole) × 7 days
Avoid oral fluconazole: even a single 150 mg dose may be associated with spontaneous abortion and congenital anomalies (CDC 2021)
Complications
Recurrent infection (5-8%)
Vulvar excoriation and secondary bacterial infection
Persistent dyspareunia and quality-of-life impact
Increased risk of preterm delivery (controversial association in pregnancy)
PANCE pearls
Vaginal pH <4.5 helps distinguish candidiasis from BV (pH >4.5) and trichomoniasis (pH >4.5).
Treat the patient, not the lab — uncomplicated VVC may be diagnosed clinically; KOH wet mount has only ~50% sensitivity.
OTC azole self-treatment frequently fails (true VVC in only ~30% of women self-treating); confirm diagnosis when patients present with treatment failure.
Non-albicans species (especially C. glabrata) are often azole-resistant — boric acid is highly effective.
Recurrent VVC warrants evaluation for diabetes and consideration of HIV; also assess vulvar skin disease (lichen sclerosus) which may mimic chronic yeast infection.
Sexual partner treatment is not indicated for routine VVC.
Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA or PAEA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants; End of Rotation™ is a program of the Physician Assistant Education Association.