Vaginal discharge — bacterial vaginosis, vulvovaginal candidiasis & aerobic vaginitis

A woman with vaginal discharge wants one thing: an answer, not a recurring mystery. The skill is in the pattern at the bedside — odour points to bacterial vaginosis, itch to candidiasis, and inflammation to aerobic vaginitis or an STI — confirmed by three cheap tests: pH paper, a drop of KOH, and a wet mount. Get those right and you will rarely send the wrong swab or give the wrong drug.[3][4]

Overview and definition

Vaginal discharge is the commonest gynaecological symptom in primary care. It is normal in most women and pathological in a defined few. The job is to separate the physiological from the pathological, then separate the pathological into its three dominant causes:[3][4]

• Bacterial vaginosis (BV) — a vaginal dysbiosis (anaerobes replace lactobacilli); the single commonest cause of pathological discharge worldwide.
• Vulvovaginal candidiasis (VVC) — overgrowth of Candida, usually albicans; an itch-and-curds picture with a normal pH.
• Aerobic vaginitis (AV) — a distinct inflammatory flora dominated by aerobic organisms (Group B strep, E. coli, S. aureus); easily confused with BV until you look down the microscope.[5]

Three other diagnoses must sit in your head alongside them, because each changes management: trichomoniasis (an STI), cervicitis (an STI until proven otherwise), and pelvic inflammatory disease (the upper-tract emergency that masquerades as "just discharge").[4]

References13Show ledgerHide ledger

1. [1]Amsel R, Totten PA, Spiegel CA, Chen KC, Eschenbach D, Holmes KK Nonspecific vaginitis. Diagnostic criteria and microbial and epidemiologic associations. Am J Med, 1983.PMID 6600371
2. [2]Nugent RP, Krohn MA, Hillier SL Reliability of diagnosing bacterial vaginosis is improved by a standardized method of gram stain interpretation. J Clin Microbiol, 1991.PMID 1706728
3. [3]Muzny CA, Balkus J, Mitchell C, Sobel JD, Workowski K, Marrazzo J, Schwebke JR Diagnosis and Management of Bacterial Vaginosis: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines. Clin Infect Dis, 2022.PMID 35416968
4. [4]Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep, 2021.PMID 34292926
5. [5]Donders GG, Vereecken A, Bosmans E, Dekeersmaecker A, Salembier G, Spitz B Definition of a type of abnormal vaginal flora that is distinct from bacterial vaginosis: aerobic vaginitis. BJOG, 2002.PMID 11845812
6. [6]Vieira-Baptista P, Lima-Silva J, Pinto C, Saldanha C, Beires J, Martinez-de-Oliveira J, Donders G Bacterial vaginosis, aerobic vaginitis, vaginal inflammation and major Pap smear abnormalities. Eur J Clin Microbiol Infect Dis, 2016.PMID 26810061
7. [7]Sobel JD, Wiesenfeld HC, Martens M, Danna P, Hooton TM, Rompalo A, Sperling M, Livengood C 3rd, Horowitz B, Von Thron J, Edwards L, Panzer H, Chu TC Maintenance fluconazole therapy for recurrent vulvovaginal candidiasis. N Engl J Med, 2004.PMID 15329425
8. [8]Sobel JD, Ferris D, Schwebke J, Nyirjesy P, Wiesenfeld HC, Peipert J, Soper D, Ohmit SE, Hillier SL Suppressive antibacterial therapy with 0.75% metronidazole vaginal gel to prevent recurrent bacterial vaginosis. Am J Obstet Gynecol, 2006.PMID 16647911
9. [9]Bradshaw CS, Tabrizi SN, Fairley CK, Morton AN, Rudland E, Garland SM The association of Atopobium vaginae and Gardnerella vaginalis with bacterial vaginosis and recurrence after oral metronidazole therapy. J Infect Dis, 2006.PMID 16941351
10. [10]Bitew A, Abebaw Y Vulvovaginal candidiasis: species distribution of Candida and their antifungal susceptibility pattern. BMC Womens Health, 2018.PMID 29902998
11. [11]Fidel PL Jr, Yano J, Esher SK, Noverr MC Applying the Host-Microbe Damage Response Framework to Candida Pathogenesis: Current and Prospective Strategies to Reduce Damage. J Fungi (Basel), 2020.PMID 32168864
12. [12]Neal CM, Kus LH, Eckert LO, Peipert JF Noncandidal vaginitis: a comprehensive approach to diagnosis and management. Am J Obstet Gynecol, 2020.PMID 31513780
13. [13]Reichman O, Sobel J Desquamative inflammatory vaginitis. Best Pract Res Clin Obstet Gynaecol, 2014.PMID 25132275