12-phase flow (12)

1. 1FRAME
   Symptomatic vaginitis in an adult — empiric symptom-only treatment is wrong ~50% of the time; anchor on a structured point-of-care workup (pH → whiff → saline/KOH microscopy → NAAT) before naming a cause (CDC STI 2021; ACOG PB 215; PMID 28594779)
   inputs: age_and_menopausal_status, discharge_character_colour_consistency
   advance: scope confirmed: symptomatic adult with abnormal discharge/pruritus/odour
2. 2ENTRY
   Recognise the presenting cluster — thin grey malodorous (BV), thick white pruritic (VVC), frothy yellow-green pruritic (trichomoniasis), or dyspareunia/dryness (atrophic) (CDC STI 2021; ACOG PB 215)
   inputs: discharge_character_colour_consistency, odour_amine_fishy
   advance: entry trigger present; provisional pre-test prior set
3. 3CONTEXT
   Menopausal/estrogen status, pregnancy, recurrence frequency, diabetes/immunocompromise, recent antibiotics, sexual activity + partners, prior episodes/treatments, nitroimidazole/azole allergy — drives complicated-vs-uncomplicated VVC, STI co-testing for trich, atrophic branch (CDC STI 2021; ACOG PB 215; Vodstrcil NEJM 2025)
   inputs: pruritus_severity, sexual_activity_and_partners, pregnancy_status, recurrence_frequency_last_year, diabetes_or_immunocompromise, nitroimidazole_or_azole_allergy
   advance: phenotype matrix populated; complicated/recurrent flags assigned
4. 4RED_FLAGS
   Escalation to a different pathway: upper-genital-tract features (cervical motion/uterine/adnexal tenderness, fever, pelvic pain) → pelvic inflammatory disease; pregnancy with symptomatic infection; suspected sexual assault/abuse; ulcerative or systemic disease; immunocompromise with severe/refractory disease (CDC STI 2021; ACOG PB 215)
   inputs: pregnancy_status
   actions: workup.vaginitis
   advance: PID/cervicitis and other escalation paths screened and routed if present
5. 5INITIAL_WORKUP
   Speculum exam + point-of-care: vaginal pH, KOH amine/whiff, saline wet mount (clue cells / motile trichomonads / PMNs / parabasal cells), 10% KOH (pseudohyphae/spores); compute Amsel for BV (CDC STI 2021; ACOG PB 215)
   inputs: vaginal_ph, amine_whiff_test, saline_wet_mount_microscopy, koh_microscopy
   actions: panel.wet_mount, calc.amsel_criteria, workup.vaginitis
   advance: point-of-care workup complete; provisional cause assigned or microscopy non-diagnostic
6. 6BRANCHING_WORKUP
   Microscopy negative but suspicion persists, or recurrent/refractory/coinfection → Nugent Gram-stain (BV reference standard; assay sens 95.0%, spec 89.6% → LR+ ~9, LR− ~0.06), vaginitis NAAT/panel (most sensitive, esp. trichomoniasis: sens 93.1–96.5%, spec 99.1–99.3% → LR+ ~95–130, LR− ~0.04–0.07), fungal culture + speciation/susceptibility (non-albicans/C. glabrata; NAAT spec 99.1–99.7%), GC/CT NAAT (cervicitis exclusion + trich STI co-testing). NAAT-over-microscopy DECISION is conditional on indication: empiric/microscopy acceptable for a concordant single-cause point-of-care pattern; NAAT > microscopy whenever trichomoniasis is plausible (wet-mount sens gap), microscopy negative with persistent suspicion, recurrent/refractory, pregnancy, immunocompromise/uncontrolled diabetes, or symptomatic-vs-screening status differs (symptomatic threshold lower) (CDC STI 2021; ACOG PB 215; PMID 31748322; PMID 28594779; PMID 30297322)
   inputs: nugent_gram_stain_score, vaginitis_naat_panel, fungal_culture_with_speciation, gc_ct_naat
   actions: calc.nugent_score, panel.wet_mount
   advance: reference/molecular testing resolves the cause and identifies non-albicans / coinfection / atrophic-GSM route-out
7. 7DIFFERENTIAL
   MECE four-way pivot — BV (clue cells, pH > 4.5, whiff+, no PMNs) vs VVC (pseudohyphae, pH ≤ 4.5, pruritus) vs trichomoniasis (motile trichomonads, pH > 4.5, PMNs, NAAT+) vs non-infective (atrophic/GSM: parabasal cells + high pH + low estrogen → route gyn.menopause-management.core.v1; DIV: purulent + parabasal + PMNs + no organism; contact/irritant; retained foreign body; physiologic). Cervicitis (GC/CT) is a SEPARATE pathway → gyn.pelvic-inflammatory-disease.core.v1. CONDITIONAL DEPENDENCES applied here, not naïve multiplication: (1) microscopy LR is operator/timing-conditioned — a negative trich saline mount (sens only ~50–70%) must NOT drop the posterior below the NAAT test-threshold; (2) pH LR+ is attenuated when blood/semen/cervical-mucus/lubricant present (confounded — not conditionally independent of whiff/clue cells); (3) Amsel and its individual components co-vary — never combined as independent (double-counting); (4) a confirmed cause does NOT zero a second cause — coinfection ~20–30% mandates explicit multi-pathogen testing when findings are mixed (clue cells + PMNs). Pre-test priors (symptomatic reproductive-age US outpatient): BV ≈ 0.45–0.50, VVC ≈ 0.20–0.30, trichomoniasis ≈ 0.04–0.10, non-infective ≈ 0.24 (CDC STI 2021; ACOG PB 215; PMID 28594779; PMID 31748322)
   inputs: vaginal_ph, saline_wet_mount_microscopy
   advance: terminal cause(s) assigned; coinfection accounted for; non-vaginitis (atrophic/GSM, cervicitis) routed out by engine_id
8. 8RISK_STRATIFICATION
   VVC uncomplicated vs COMPLICATED (severe; ≥ 3/yr; non-albicans; pregnancy; uncontrolled diabetes/immunocompromise); BV uncomplicated vs recurrent (≥ 3/yr — suppressive pathway); trichomoniasis always STI-tier (partner + co-test + retest) (CDC STI 2021; ACOG PB 215; Sobel NEJM 2004)
   inputs: recurrence_frequency_last_year, diabetes_or_immunocompromise
   advance: complexity tier set; regimen route (single-dose vs induction+suppression) chosen
9. 9TREATMENT
   BV: metronidazole 500 mg PO BID × 7 d OR 0.75% metronidazole gel × 5 d OR 2% clindamycin cream × 7 d; secnidazole 2 g PO × 1 / tinidazole alternatives; recurrent BV → metronidazole gel twice-weekly × ≥ 3–6 mo (boric-acid-adjunct for intractable RBV, PMID 34110746; consider male-partner combination therapy, Vodstrcil NEJM 2025). VVC uncomplicated: fluconazole 150 mg PO × 1 OR topical azole; complicated/severe: fluconazole q72h × 2–3; recurrent VVC: induction (fluconazole q72h × 3) → fluconazole 150 mg weekly × 6 mo (Sobel NEJM 2004) / ReCiDiF degressive / oteseconazole (PMID 38319878) / ibrexafungerp (PMID 36255448); non-albicans → boric acid 600 mg PV × 14 d ± topical flucytosine; pregnancy → 7-d topical azole only. Trichomoniasis: metronidazole 500 mg PO BID × 7 d for WOMEN (Kissinger Lancet ID 2018 — superior to single 2 g), men 2 g × 1, tinidazole 2 g × 1 alternative; treat all partners; nitroimidazole allergy → desensitisation. Counsel alcohol–metronidazole avoidance (CDC STI 2021; ACOG PB 215)
   inputs: pregnancy_status, nitroimidazole_or_azole_allergy
   advance: cause-specific regimen + partner-management + counselling plan set
10. 10DISPOSITION
    Outpatient management for all; refer/route if PID/cervicitis, pregnancy with symptomatic infection, recurrent/refractory needing specialist (vulvovaginal-disorders clinic), suspected non-albicans requiring compounded therapy, or diagnostic uncertainty after full workup (CDC STI 2021; ACOG PB 215)
    advance: outpatient plan confirmed; specialist referral made if indicated
11. 11MONITORING
    No test-of-cure if asymptomatic resolution (BV/uncomplicated VVC). Reassess if symptoms persist/recur — re-examine + culture/NAAT, consider non-albicans or alternative diagnosis (incl. atrophic/GSM route-out in postmenopausal). Trichomoniasis: retest 3 months after treatment (high reinfection — CDC STI 2021). Recurrent VVC on fluconazole suppression: monitor LFTs if prolonged, watch breakthrough; recurrent BV on metronidazole gel: monitor for secondary VVC (PMID 34110746). Adjuvant L. crispatus live biotherapeutic (LACTIN-V) for recurrent BV is CONDITIONALLY effective — only after documented post-antibiotic clinical cure (RR 0.56, 95% CI 0.35–0.77 if cured vs 1.34, 95% CI 0.47–2.23 if not — PMID 38733973); LACTIN-V also sustains reduced genital inflammation post-treatment (PMID 35659905) (CDC STI 2021; Sobel NEJM 2004)
    inputs: recurrence_frequency_last_year
    actions: panel.wet_mount
    advance: symptom resolution confirmed or recurrence/refractory/atrophic pathway triggered
12. 12FOLLOWUP
    Trichomoniasis: HIV + syphilis screen at diagnosis, partner treatment (expedited partner therapy where legal), pelvic rest until both treated + asymptomatic, 3-month repeat-infection retest. Recurrent VVC: ≥ 6-month maintenance plan, glycaemic optimisation, irritant avoidance. Recurrent BV: long-term suppression plan, condom/partner-treatment counselling, probiotic/vaginal-microbiome discussion (limited evidence). Education on trigger avoidance and accurate self-vs-clinician diagnosis limits (CDC STI 2021; ACOG PB 215; Vodstrcil NEJM 2025)
    inputs: hiv_and_sti_serology
    actions: workup.vaginitis
    advance: partner/STI plan, suppression plan, retest schedule, and education documented