Vaginitis: Candida, BV & Trichomoniasis

Vulvovaginitis (AKA Vaginitis) is inflammation of the lower genital tract. It is usually due to infection, but there are a wide variety of causes. During this video we will focus on the three most important causes of vulvovaginitis for the medical board exam (trichomonas, candida and BV). However, you should know that other types of vaginitis include mechanical irritation, allergic reactions (to soaps or feminine products) and a variety of other infections. Gonorrhea and Chlamydia present primarily with cervicitis, but it can also cause vulvovaginitis. G/C will be covered later in its own video. Atrophic Vaginitis is a common cause of vaginitis in post-menopausal women and we will cover that in a later video in the GYN section.


Wet Prep (AKA Wet Mount Test) – microscopic examination of vaginal discharge used to differentiate between different types of vulvovaginitis. The vaginal specimen is obtained using a speculum and a que tip similar to how one gets a pap smear. Then the specimen is rubbed onto a glass slide. One half of the slide has a drop of saline added to it while the other half of the slide has a drop of 10-20% KOH (Potassium hydroxide) added to it.

  • When Saline is added it makes it easier to view clue cells for BV & flagellated motile cells for trichomonas.
  • The KOH kills bacteria and vaginal cells leaving only yeast cells. This makes it easier to view the psuedohyphae and budding yeast present during vulvovaginal candidiasis.
  • KOH is also alkalotic so it can be used for a “Whiff Test.” In this scenario when the alkalotic KOH is added to a sample containing BV it will create an amine or fishy smell. This is a similar principle behind how the smell of BV can increase after unprotected sex since semen is alkalotic.


The normal vaginal pH for a reproductive age woman is about 4, while the normal vaginal pH before puberty and after menopause is about 7. During puberty there is an estrogen guided increase in the growth lactobacilli flora. These bacteria break down glycogen into lactic acid which lowers pH from about 7 to about 4. Now that you know the normal values you can apply it to diseases. Usually, Bacterial Vaginosis & Trichomonas have alkalotic pH (>4.5 in reproductive age women) while candida has normal pH (<4.5). pH paper can be tested by using pH paper on vaginal discharge.


Bacterial Vaginosis (AKA BV) is a polymicrobial infection caused by the overgrowth of normal flora. The key bacteria in this infection is gram negative Gardnerella Vaginalis.

  • Clue cells are visible on the saline portion of a wet prep. A Clue Cell is a sloughed mucosal squamous epithelial cell covered in many adherent coccoid bacteria (Gardenerella Vaginalis).
  • A thin/watery gray-white discharge is present
  • A fouls smell is present and often described as an Amine Odor or Fishy Smell. This smell is intensified after unprotected intercourse or when KOH is added (AKA Positive Whiff Test).
  • Alkalotic pH (>4.5 in reproductive age woman)
  • Minimal itching and inflammation/erythema is present. Few leukocytes visible on microscopy
  • Treatment = topical Metronidazole or oral metronidazole if that doesn’t work. Clindamycin is another option

Clue Cell 1

Clue Cell 2

Clue Cell 3

Vulvovaginal Candidiasis (AKA Yeast Infection) is an overgrowth of ubiquitous fungi. The most common subtype of candida infections in the vaginal tract is Albicans, but you also see Glabrata and Tropicalis (especially if it is resistant to treatment).

  • Mostly happens in patients with altered flora (immunosuppressed, antibiotic therapy, corticosteroids) of increased glycogen (diabetics, pregnant, OCPs)
  • Keeping the vagina moist and warm with tightfitting clothing like a bathing suit also is a risk factor
  • Severe inflammation leads to bright red erythema, vulvar pruritus (severe itching), burning, dysuria (painful urination) & dyspareunia (painful intercourse). Many leukocytes are seen on microscopic examination
  • Lumpy/Thick adherent white cottage cheese like discharge
  • Odorless
  • Normal pH
  • Budding yeast & psuedohyphae seen on the KOH portion of a wet prep
  • Treatment = OTC topical miconazole (monostat), oral fluconazole (diflucan) & or topical terconazole(Terazol)


Trichomoniasis (AKA Trichomonas Vaginalis) is a very contagious STD, therefore the question stem will almost always mention unprotected sexual activity.

  • Inflammation leads to burning, itching, erythema, dysuria and dyspareunia. Many leukocytes are seen on microscopic examination
  • Patchy Erythema on cervix is referred to as Strawberry Petechiae. Note that this finding can be easily confused with Cervicitis (Gon/Chlyamdia).
  • Thin/watery frothy (bubbly) yellow-green discharge
  • On Saline prep see motile flagellate protozoa/trophozoites
  • Can have malodorous/fishy smell/foul smell
  • Alkalotic pH (>4.5 in reproductive age)
  • Treatment = oral metronidazole for both partners to prevent reinfection

Trich 1

Trich 2

List of unique characteristics:

  • Trich = STD
  • Trich = Motile organisms
  • Trich = Strawberry petechiae on cervix
  • Candida = normal pH
  • Candida = Psuedohyphae & budding yeast
  • BV = Clue Cells
  • BV = Minimal itching/inflammation


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