What is the recommended evaluation and management for a 20‑year‑old woman with monthly pre‑menstrual vulvar itching, burning, recurrent inner labial bumps, and non‑odorous white‑yellow vaginal discharge, given a new sexual partner and a history of treated chlamydia?

Cyclic Vulvovaginal Candidiasis with Possible Concurrent STI

This patient most likely has cyclic vulvovaginal candidiasis (VVC) triggered by hormonal fluctuations, but given her new sexual partner and history of chlamydia, you must first rule out concurrent sexually transmitted infections before treating the presumed yeast infection.

Immediate Diagnostic Evaluation

Essential Testing Required

• Wet mount microscopy with KOH preparation to visualize yeast/pseudohyphae and assess for clue cells or trichomonads 1
• Vaginal pH testing (VVC associated with pH ≤4.5; BV or trichomoniasis with pH >4.5) 1
• Nucleic acid amplification testing (NAAT) for chlamydia and gonorrhea from cervical or vaginal specimens given new sexual partner within 5 months 1, 2, 3
• Consider trichomoniasis NAAT given the non-odorous discharge and new partner, though the cyclic pattern and white-yellow discharge favor candidiasis 1, 4

Clinical Examination Specifics

• Examine the labial bumps directly during an outbreak to distinguish between vesicular lesions (herpes), erythematous papules (candidiasis), or other lesions 4, 5
• Look for vulvar erythema and vaginal erythema which support VVC diagnosis 1
• Assess for cervical motion tenderness or adnexal tenderness to exclude pelvic inflammatory disease 1

Diagnostic Reasoning

The monthly pre-menstrual timing with resolution after menses strongly suggests cyclic VVC, which occurs in a subset of women due to progesterone-mediated changes in vaginal glycogen and pH 1. The white-yellow non-odorous discharge and vulvar itching/burning are classic for candidiasis rather than bacterial vaginosis (which typically has fishy odor) or trichomoniasis (which typically has yellow-green malodorous discharge) 1, 4.

However, herpes cannot be definitively excluded without examining lesions during an outbreak. The cyclic pattern is atypical for herpes, which usually presents with painful vesicles/ulcers rather than "bumps" and doesn't follow menstrual cycles 4, 5. The new sexual partner mandates STI screening regardless of symptom pattern 1, 3.

Treatment Algorithm

If Wet Mount Confirms Yeast and STI Testing is Negative

For acute episodes:

• Fluconazole 150 mg oral single dose is most convenient 1, 4
• Alternative: Any topical azole (miconazole 200 mg suppository for 3 days, or clotrimazole 100 mg tablet for 7 days) 1

For recurrent VVC (≥4 episodes per year, which this patient likely has):

• Initial treatment: Fluconazole 150 mg on days 1,4, and 7 to achieve remission 1
• Maintenance suppression: Fluconazole 150 mg weekly for 6 months to prevent recurrences 1
• Obtain vaginal culture before starting suppressive therapy to identify non-albicans species (particularly C. glabrata), which may require alternative treatment 1

If Chlamydia is Detected

Treat with doxycycline 100 mg orally twice daily for 7 days (preferred over azithromycin per 2021 CDC guidelines) 1, 2, 6, 3. Treat the sexual partner and instruct abstinence until both complete treatment 1, 3. Retest in 3 months due to high reinfection rates 1.

If Trichomoniasis is Detected

Treat with metronidazole 500 mg orally twice daily for 7 days (preferred over single-dose therapy per recent guidelines) 1, 2, 4. Treat the partner and ensure abstinence until both are cured 1.

Critical Pitfalls to Avoid

• Do not assume recurrent symptoms are always the same infection without repeat examination and testing 7, 5
• Do not use over-the-counter antifungals without confirmed diagnosis in this patient, as inappropriate self-treatment delays diagnosis of STIs and can worsen outcomes 1
• Do not overlook partner treatment if STI is diagnosed, as this is the primary cause of treatment failure and reinfection 1
• Do not prescribe topical steroids empirically for vulvar symptoms without establishing diagnosis, as this can worsen infections 7, 5
• Recognize that multiple conditions can coexist (e.g., VVC with concurrent chlamydia), requiring treatment of both 1

Follow-Up Strategy

• Return visit only if symptoms persist after treatment or recur within 2 months 1
• If recurrences continue despite suppressive therapy, consider non-albicans Candida species, medication non-adherence, reinfection from untreated partner, or alternative diagnoses including vulvar dermatoses 1, 8, 5
• Retest for chlamydia in 3 months if initially positive, regardless of partner treatment status 1, 2