Vaginal discharge causes and diagnosis
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Causes of Vaginal Discharge: Physiological and Pathological
Vaginal discharge is a very common symptom in women of all ages and can be either physiological (normal) or pathological (abnormal). Normal discharge is influenced by hormonal changes, menstrual cycles, and the presence of healthy vaginal flora, mainly lactobacilli, which help maintain a protective acidic environment . Each woman has her own baseline for what is considered normal discharge, and this can change over time .
Pathological vaginal discharge is most often caused by infections or disturbances in the vaginal ecosystem. The most common infectious causes are:
- Bacterial vaginosis (BV): This is the leading cause of abnormal vaginal discharge, resulting from an imbalance in the vaginal bacteria. BV is often associated with a thin, grayish discharge and a fishy odor. It is more common in women with new or multiple sexual partners but can also occur in women who are not sexually active 134567810.
- Vulvovaginal candidiasis (VVC): This yeast infection, usually caused by Candida albicans, leads to thick, white, "cottage cheese-like" discharge and itching. It affects up to 75% of women at least once in their lives 134567810.
- Trichomoniasis: This sexually transmitted infection is characterized by copious, yellow-green, frothy discharge and may be accompanied by irritation or odor 34567810.
Other less common causes include aerobic vaginitis, cytolytic vaginosis, atrophic vaginitis (especially in postmenopausal women), allergic or irritant reactions, and rarely, cervical or vaginal cancers 25710.
Diagnostic Approaches for Vaginal Discharge
Clinical Assessment and History
A thorough history and physical examination are essential. Important factors include the color, consistency, and odor of the discharge, associated symptoms (itching, burning, pain), sexual history, and risk factors for sexually transmitted infections (STIs) 4510.
Office-Based and Laboratory Testing
- Microscopy and pH Testing: Simple, rapid tests such as wet mount microscopy, vaginal pH measurement, and the "whiff test" (amine odor test) are first-line tools for differentiating between BV, VVC, and trichomoniasis 235689.
- Gram Stain and Nugent’s Score: Gram staining of vaginal fluid is the gold standard for diagnosing BV, with the Nugent score providing a quantitative assessment of bacterial types 35.
- Culture and Molecular Tests: Cultures are especially useful for diagnosing candidiasis and trichomoniasis, particularly in recurrent or complicated cases. PCR and nucleic acid amplification tests are recommended for detecting STIs such as chlamydia, gonorrhea, and Mycoplasma genitalium, and are also used for trichomoniasis 25.
- Pap Smear: This test can help identify cervical pathology, including precancerous changes, and is recommended as part of the evaluation in some cases .
Syndromic Management
In settings where laboratory resources are limited, syndromic management based on symptoms and simple office tests is recommended, following WHO guidelines. However, this approach may lead to over- or under-treatment, so laboratory confirmation is preferred when possible 368.
Conclusion
Vaginal discharge can result from a variety of physiological and pathological causes, with bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis being the most common infectious etiologies. Accurate diagnosis relies on a combination of clinical assessment and targeted laboratory tests, including microscopy, pH testing, Gram stain, culture, and molecular methods. Identifying the specific cause is crucial for effective treatment and to avoid unnecessary or inappropriate therapy 12345678+2 MORE.
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