Introduction
Normal Physiological Discharge
- White or clear appearance
- Non-offensive odor
- Varies throughout menstrual cycle
- Changes with hormonal fluctuations
Abnormal Discharge Characteristics
- Change in color (yellow, green, grey)
- Altered consistency (curdy, frothy, thin)
- Increased volume
- Offensive or fishy odor
- Associated with symptoms:
- Itching or soreness
- Dysuria
- Pelvic pain
- Intermenstrual bleeding
- Postcoital bleeding
Causes of Abnormal Vaginal Discharge
Vaginal Infections
- Bacterial vaginosis
- Vulvovaginal candidiasis
- Trichomoniasis
- Aerobic vaginitis
Endocervical Infections
- Chlamydia trachomatis
- Neisseria gonorrhoeae
- Pelvic inflammatory disease
- Mycoplasma genitalium
Non-infective Causes
- Retained foreign body
- Allergic/irritant reactions
- Genital tract tumors
- Atrophic vaginitis
- Cervical ectopy/polyps
- Fistulae
- Postpartum/surgical
Common Vaginal Infections Comparison
| Feature | Bacterial Vaginosis | Trichomoniasis | Vaginal Candidiasis |
|---|---|---|---|
| Cause | Anaerobic overgrowth (Gardnerella) | Trichomonas vaginalis (STI) | Candida albicans (fungal) |
| Discharge | Thin, grey/white, fishy odor | Yellow-green, frothy, offensive | White, curdy, odorless |
| Associated Symptoms | Usually no itching/soreness | Itching, soreness, dysuria, abdominal pain | Vulval itching, soreness, dysuria |
| Examination Findings | Homogeneous coating, no inflammation | Frothy discharge, vulvitis, strawberry cervix | Erythema, fissuring, excoriations |
| Vaginal pH | >4.5 | >4.5 | ≤4.5 |
| Investigations | High vaginal swab, Gram stain | High vaginal swab, microscopy | Fungal culture if recurrent |
| Treatment | Metronidazole 400mg BD 5-7 days | Metronidazole 400-500mg BD 5-7 days | Antifungal cream/pessary or oral fluconazole |
Normal Discharge
White/clear, non-offensive, varies cyclically
Bacterial Vaginosis
Thin, grey/white, fishy odor, pH >4.5
Trichomoniasis
Yellow-green, frothy, offensive, pH >4.5
Candidiasis
White, curdy, odorless, pH ≤4.5
Bacterial Vaginosis (BV)
Key Facts
- Most common cause of abnormal discharge
- Anaerobic bacterial overgrowth
- Gardnerella vaginalis predominant
- ~50% of women asymptomatic
Clinical Features
Symptoms
- Fishy-smelling discharge
- Thin, grey/white consistency
- Homogeneous coating
- Usually no itching/soreness
Examination
- Thin white/grey discharge
- Coats vaginal walls/vulva
- Fishy odor (especially after sex)
- No signs of inflammation
Investigations
- Vaginal pH >4.5
- High vaginal swab
- Gram staining
- Whiff test positive
Management
Complications & Risks
- Increased STI acquisition risk
- Pelvic inflammatory disease
- Post-operative infections
- Obstetric complications:
- Preterm labor
- Premature rupture of membranes
- Chorioamnionitis
Trichomoniasis
Sexual Health Referral
Refer to GUM clinic or specialist sexual health service for confirmation and management
Clinical Features
Symptoms
- Frothy yellow-green discharge
- Offensive odor
- Vulval itching/soreness
- Dysuria, dyspareunia
- Lower abdominal pain
- ~50% asymptomatic
Examination
- Yellow-green frothy discharge
- Offensive odor
- Vulvitis and vaginitis
- Strawberry cervix (rare)
- Vaginal inflammation
Investigations
- Vaginal pH >4.5
- High vaginal swab
- Microscopy for motile trichomonads
- NAAT testing if available
Management
Complications
- Perinatal complications
- Preterm delivery
- Low birth weight
- Postpartum sepsis
- Increased HIV transmission
- Pelvic inflammatory disease
- Increased cervical cancer risk
- Infertility
Vulvovaginal Candidiasis (VVC)
Risk Factors
- Oestrogen exposure
- Immunocompromised state
- Poorly controlled diabetes
- Broad-spectrum antibiotics
- Local irritants
- Contraception/HRT use
Clinical Features
Symptoms
- Vulval itching (defining symptom)
- Vulval soreness and irritation
- White, 'cheese-like' discharge
- Non-malodorous
- Superficial dyspareunia
- Dysuria (external)
Severe Signs
- Erythema of vagina/vulva
- Extension to labia majora
- Vaginal fissuring/oedema
- Vulval excoriation
- Extensive inflammation
Investigations
- Vaginal pH ≤4.5
- High vaginal swab if uncertain
- Fungal culture if recurrent
- Speciated culture if treatment failure
Management
Diagnostic Approach
Vaginal Discharge Diagnostic Algorithm
Step-by-step diagnostic approach for vaginal discharge
Key Diagnostic Tests
| Test | Purpose | Interpretation |
|---|---|---|
| Vaginal pH | Differentiate between causes | >4.5 suggests BV or TV; ≤4.5 suggests VVC |
| Whiff Test | Detect fishy odor | Positive in BV, may be positive in TV |
| Microscopy | Identify organisms | Clue cells (BV), trichomonads (TV), hyphae (VVC) |
| High Vaginal Swab | Culture and sensitivity | Confirm diagnosis, identify non-albicans Candida |
| NAAT Testing | Detect STIs | Chlamydia, gonorrhoea, Trichomonas |