Can VVC Cause Leukocytes in Urine?
No, vulvovaginal candidiasis (VVC) does not directly cause pyuria (leukocytes in urine), but leukocyte esterase testing can produce false-positive results when vaginal discharge contaminates the urine specimen.
The Key Distinction: Vaginal vs. Urinary Leukocytes
VVC causes an inflammatory response in the vagina and vulva, not in the urinary tract 1. The leukocytes associated with VVC are present in vaginal secretions, not in the urine itself 2.
Why Confusion Occurs
- Specimen contamination is the primary mechanism by which VVC appears to cause pyuria 2
- When collecting a urine sample, vaginal discharge containing leukocytes can contaminate the specimen, leading to a positive leukocyte esterase test 2
- A 1985 study demonstrated that leukocyte esterase dipstick testing was 100% sensitive and 100% specific for detecting true urinary tract infections, but also detected vaginal infections when vaginal discharge contaminated the urine sample 2
Clinical Implications
If a patient with VVC has leukocytes detected in urine, consider these possibilities:
- Contaminated specimen: The most likely explanation—vaginal discharge with leukocytes has mixed with the urine during collection 2
- Concurrent UTI: VVC and urinary tract infections can coexist, particularly in women with risk factors for both conditions 2
- Other vaginal infections: Trichomonas vaginalis causes significant vaginal leukocytosis and commonly produces positive leukocyte esterase results even when urine cultures are negative 2
Practical Approach
To differentiate true pyuria from contamination:
- Obtain a catheterized or suprapubic urine specimen if clinical suspicion for UTI is high and you need to rule out contamination
- Perform urine microscopy in addition to dipstick testing—true pyuria shows leukocytes uniformly distributed throughout the urine, while contamination may show clumping or association with epithelial cells
- Consider the clinical context: VVC typically presents with vulvovaginal symptoms (pruritus, discharge, dyspareunia) without urinary symptoms like dysuria or frequency, though external dysuria from vulvar inflammation can occur 1, 3
Common Pitfall to Avoid
Do not automatically treat for a UTI based solely on a positive leukocyte esterase test in a patient with known or suspected VVC 2. The positive result may reflect vaginal inflammation rather than urinary tract infection, leading to unnecessary antibiotic use.