Vaginitis refers to inflammation or infection of the vagina.  The two most common causes are vulvovaginal candidiasis (yeast infection) and trichomoniasis. Chlamydia and gonorrhea may cause similar symptoms, but these infections are usually more specific to to the cervix or urethra. Not all vaginitis is infectious. Genitourinary syndrome of menopause (atrophic changes), irritant or allergic reactions, and inflammatory conditions can also cause vaginal symptoms.  Bacterial Vaginosis (BV) refers to an abnormal condition of the vagina, typically involving an imbalance of its normal bacterial flora, rather than inflammation. 

Bacterial Vaginosis (BV)​

• Mechanism: A shift away from healthy, acid-producing Lactobacillus species toward an overgrowth of anaerobic bacteria (such as Gardnerella vaginalis, Atopobium vaginae, and Prevotella species).

• Vaginal pH: Rises above normal (pH greater than 4.5).

Vulvovaginal Candidiasis (Yeast Infection)​​
 

• Mechanism: Occurs when conditions allow normal yeast populations to proliferate rapidly and invade superficial mucosal cells.

• Vaginal pH: Remains normal (pH less than or equal to 4.5).
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Trichomonas Vaginalis
 

• Mechanism: The parasite infects the vagina, urethra, and surrounding genital tissues, causing inflammation. Many infected people have few or no symptoms.

• Vaginal pH: Usually >4.5. C

• Considered a sexually transmitted disease

Symptoms & Clinical Features

Bacterial Vaginosis (BV)
 

• Discharge: Thin, watery, homogeneous, off-white or grayish discharge that coats the vaginal walls evenly.

• Odor: Strong, stale "fishy" odor that becomes noticeably stronger after sexual intercourse or during menstruation (alkaline semen and blood trigger the release of volatile amines).

• Irritation/Pain: Usually none or very mild

• Tissue Appearance: Vaginal mucosa and vulva usually look normal without significant redness or swelling.

Vulvovaginal Candidiasis
 

• Discharge: Thick, white, clumpy discharge with a texture resembling cottage cheese. Typically odorless.

• Odor: None, or a mild yeast/bread-like smell.

• Irritation/Pain: Intense vulvar itching (pruritus), burning (especially during urination when urine touches inflamed skin), and painful intercourse (dyspareunia).

• Tissue Appearance: Marked erythema (redness), swelling, and excoriation (raw, cracked skin) of the vulva and vagina.

Trichomoniasis
 

• Discharge: May cause increased vaginal discharge that is thin or frothy and can be yellow-green, although appearance varies considerably.

• Odor: May have an unpleasant or fishy odor.

• Irritation/Pain: Vulvar itching, burning, redness, painful urination, or pain during intercourse may occur.

• Tissue Appearance: Vaginal and vulvar inflammation may occur. A “strawberry cervix” (small red spots on the cervix) is a classic finding but is not present in most patients.

• Many people with trichomoniasis have minimal or no symptoms.

Causes & Risk Factors
 

BV Risk Factors
 

• Douching or Intravaginal Washing: Flushes out protective Lactobacilli and alters natural vaginal acidity.

• New or Multiple Sexual Partners: Alters vaginal flora dynamics (though BV is not classified strictly as an STI).

• Lack of Barrier Protection: Semen (alkaline pH) temporarily neutralizes protective vaginal acidity.

• Cigarette Smoking: Linked to decreased Lactobacillus colonization.

Vulvovaginal Candidiasis Risk Factors
 

• Recent Antibiotic Use: Broad-spectrum antibiotics kill off protective Lactobacillus bacteria, allowing fungal species to overgrow.

• Elevated Estrogen / Glycogen Levels: Pregnancy, combined oral contraceptives, or high-dose estrogen therapy.

• Poorly Controlled Diabetes: Elevated glucose levels in vaginal secretions promote fungal growth.

• Immunosuppression: HIV, systemic steroid use, or chemotherapy.

• Moisture Retention: Wearing tight, synthetic (non-breathable) underwear or remaining in wet bathing suits/exercise clothes for prolonged periods.

Trichomoniasis Risk Factors
 

• Sexual contact with an infected partner

• New or multiple sexual partners

• Inconsistent condom use

• Previous or concurrent sexually transmitted infections

Complications
 

Bacterial Vaginosis (BV) increases the risk for:
 

• pregnancy complications (preterm labor, low birth weight).

• acquiring or transmitting STIs (including HIV).

• pelvic infections / pelvic inflammatory disease

Vulvovaginal Candidiasis increases the risk for:
 

• Skin breakdown and damage from inflammation and scratching

Trichomoniasis increases the risk for:
 

• Acquiring or transmitting HIV

• Other sexually transmitted infections

• Pregnancy complications, including preterm birth and low birth weight

• Persistent or recurrent infection when sexual partners are not treated

Diagnostics

Amsel Criteria for BV (Requires at least 3 of 4):
 

1. Homogeneous, thin, off-white discharge.

2. Vaginal pH > 4.5

3. Positive Whiff Test (a distinct fishy amine odor released immediately after adding 10% potassium hydroxide [KOH] to a discharge sample).

4. Clue Cells on wet mount microscopy (vaginal epithelial cells stippled/coated with bacteria, obscuring their clean cellular borders).

Vulvovaginal Candidiasis:
 

• 10% KOH Preparation / Saline Wet Mount: Microscopic visualization of budding yeast cells, pseudohyphae, or hyphae.

• Vaginal Culture / PCR: Indicated for recurrent cases, treatment failures, or suspected non-albicans species (such as Candida glabrata).

• Vaginal pH: Remains normal (pH less than or equal to 4.5)

Trichomoniasis
 

• NAAT (Nucleic Acid Amplification Test)

• Wet Mount Microscopy: May demonstrate motile trichomonads, but sensitivity is limited and decreases rapidly after the specimen is collected.

• Vaginal pH: Usually >4.5.

Treatment & Management

Bacterial Vaginosis (BV)
 

• First-Line Regimens:

  • Metronidazole (Flagyl): 500 mg orally twice daily for 7 days

  • Metronidazole 0.75% Gel: 1 full applicator (5 grams) intravaginally once daily at bedtime for 5 days.

  • Clindamycin 2% Cream: 1 full applicator (5 grams) intravaginally at bedtime for 7 days. (Note: Clindamycin cream can weaken latex condoms and diaphragms).
     

Avoid douching and intravaginal cleansing — These practices disrupt normal vaginal bacteria and are associated with both development and recurrence of BV. Use condoms consistently — Lack of condom use is associated with increased BV risk. Limit new or multiple sexual partners — New and multiple partners are associated with increased risk of BV.

Vulvovaginal Candidiasis

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• Uncomplicated Cases (Mild-to-Moderate, Infrequent):

  • Oral Antifungal: Fluconazole (Diflucan) 150 mg orally as a single-dose tablet.

  • Topical Antifungals (OTC or Rx): Clotrimazole, Miconazole, or Terconazole intravaginal creams or suppositories for 1, 3, or 7 days.

• Complicated / Recurrent Cases (greater than or equal to 3 episodes per year):

  • Fluconazole 150 mg orally every 72 hours for 3 doses (Days 1, 4, and 7), followed by weekly maintenance fluconazole (150 mg) for 6 months.
     

Avoid unnecessary antibiotic use — Antibiotics can disrupt normal vaginal bacteria and increase the risk of Candida overgrowth. Maintain good diabetes control — Poorly controlled diabetes and elevated blood glucose can increase susceptibility to yeast infections. Avoid unnecessary vaginal products and douching — These can cause irritation and alter the vaginal environment. Keep the vulvar area clean and dry — Wash the external vulva gently with water or mild, unscented soap and avoid irritating scented products.

Trichomoniasis
 

• Women: Metronidazole 500 mg orally twice daily for 7 days.

• Men: Metronidazole 2 grams orally as a single dose.

• Alternative: Tinidazole 2 grams orally as a single dose.

Sexual partners should also be treated to prevent reinfection. Patients should avoid sexual intercourse until they and their partners have completed treatment and symptoms have resolved. Because reinfection is common, the CDC recommends retesting sexually active women approximately 3 months after treatment, regardless of whether they believe their partners were treated. Avoid sexual intercourse until treatment has been completed by both the patient and partner(s). Condoms can reduce rates of transmission. 

                                                       
                                                             References & Guidelines
 

• Centers for Disease Control and Prevention (CDC). Sexually Transmitted Infections Treatment Guidelines: Bacterial Vaginosis.

• Centers for Disease Control and Prevention (CDC). Sexually Transmitted Infections Treatment Guidelines: Vulvovaginal Candidiasis.

• Centers for Disease Control and Prevention (CDC). Sexually Transmitted Infections Treatment Guidelines: Trichomoniasis.