I. Introduction to Pyuria
Pyuria is defined as the presence of an abnormally high number of white blood cells (WBCs) in the urine, indicating inflammation or infection in the urinary tract. It is a significant clinical marker for differentiating infectious and non-infectious conditions affecting the kidneys, bladder, ureters, and urethra.
πΉ Normal Urine WBC Count: < 5 WBCs/hpf (high-power field)
πΉ Significant Pyuria: >10 WBCs/hpf in centrifuged urine
II. Etiology of Pyuria
A. Infectious Causes
| Condition | Common Pathogens | Key Features |
|---|---|---|
| Urinary Tract Infection (UTI) | E. coli, Klebsiella, Proteus, Staph. saprophyticus | Dysuria, urgency, fever |
| Pyelonephritis | E. coli, Pseudomonas, Enterococcus | Flank pain, fever, nausea, WBC casts |
| Prostatitis (Males) | E. coli, Chlamydia, Gonorrhea | Perineal pain, tender prostate |
| Tuberculosis (Renal TB) | Mycobacterium tuberculosis | Sterile pyuria, hematuria, weight loss |
| Fungal UTI (Candiduria) | Candida albicans | Common in diabetics, catheterized patients |
B. Non-Infectious Causes
| Condition | Mechanism | Key Features |
|---|---|---|
| Interstitial Nephritis | Drug-induced allergic reaction | Rash, eosinophilia, fever |
| Glomerulonephritis | Immune complex deposition | Proteinuria, hematuria, RBC casts |
| Renal Stones (Nephrolithiasis) | Mechanical irritation | Flank pain, hematuria |
| Autoimmune Diseases | Inflammatory response | Lupus nephritis, vasculitis |
| Malignancy (Bladder/Kidney Cancer) | Tumor invasion | Painless hematuria |
III. Pathophysiology of Pyuria
- Leukocyte Infiltration: WBCs migrate to the urinary tract in response to infection or inflammation.
- Cytokine Release: IL-6, TNF-Ξ±, and other inflammatory mediators trigger immune activation.
- Epithelial Damage: Persistent inflammation can lead to tissue damage and fibrosis.
Sterile Pyuria (No Bacterial Growth in Culture)
- Renal TB
- Interstitial Nephritis (NSAIDs, Penicillin, Sulfa drugs)
- Malignancy (Bladder/Kidney cancer)
- Autoimmune disorders (SLE, Vasculitis)
πΉ Key Differentiation: Urine culture, AFB stain (TB), ANA/ANCA (Autoimmune), CT Urography (Malignancy)
IV. Clinical Presentation & Evaluation
| Symptom | Infectious Pyuria | Sterile Pyuria |
|---|---|---|
| Dysuria (Burning Urination) | β Common | β Absent |
| Fever & Chills | β High-grade (Pyelonephritis) | β Absent |
| Flank Pain | β Pyelonephritis, Renal TB | β Renal stones |
| Hematuria | β Sometimes | β Common in cancer, glomerulonephritis |
| Proteinuria | β Minimal | β Glomerular diseases |
V. Diagnostic Approach to Pyuria
Stepwise Investigation Protocol
1οΈβ£ Urinalysis (Dipstick & Microscopy)
- Leukocyte Esterase (Detects WBCs)
- Nitrites (Indicates Gram-negative bacteria)
- WBC Casts (Pyelonephritis, Interstitial Nephritis)
2οΈβ£ Urine Culture (Gold Standard for Infection)
- Bacterial count >10β΅ CFU/mL confirms UTI.
- Sterile culture? β Think TB, Interstitial Nephritis
3οΈβ£ Advanced Urine Tests
- AFB Staining & Urine PCR (for Renal TB)
- Cytology & Tumor Markers (for Bladder Cancer)
4οΈβ£ Imaging Studies
- CT Urography (Stone, Malignancy, TB Abscesses)
- Renal Ultrasound (Obstruction, Hydronephrosis, Masses)
VI. Modern Techniques for Pyuria Quantification
| Technique | Application |
|---|---|
| Flow Cytometry (FCM) | Rapid WBC quantification |
| Phase-Contrast Microscopy | Differentiates WBC types |
| Automated Urinalysis (Sysmex UF-5000) | High-accuracy WBC count |
VII. Pyuria in Special Conditions
A. Pregnancy & Pyuria
- Asymptomatic Bacteriuria (ABU) β High UTI risk
- Complications: Preterm labor, pyelonephritis
- Treatment: Nitrofurantoin, Cephalexin (Avoid Fluoroquinolones)
B. Diabetes & Pyuria
- More prone to Fungal UTI (Candiduria)
- Emphysematous Pyelonephritis (EPN) β Gas-forming E. coli in diabetics
- Urine Glucose β Bacterial Growth Medium
C. Chronic Kidney Disease (CKD) & Pyuria
- Sterile Pyuria β Tubulointerstitial Nephritis (TIN)
- Progressive renal decline β Check Proteinuria, eGFR
VIII. Management of Pyuria
1. Treat Underlying Cause
| Condition | Treatment Approach |
|---|---|
| UTI | Antibiotics (Nitrofurantoin, TMP-SMX, Fosfomycin) |
| Pyelonephritis | IV Ceftriaxone, Fluoroquinolones |
| Renal TB | 6-month ATT (Isoniazid, Rifampin) |
| Kidney Stones | Hydration, Lithotripsy (if large) |
| Bladder Cancer | Cystoscopy + TURBT |
2. Supportive Measures
β
Hydration (3L/day) β Flush out infections
β
Cranberry Extract β Prevents E. coli adhesion
β
Probiotics (Lactobacillus) β Reduces UTI recurrence
β
Avoid Unnecessary Catheterization β Reduces UTI risk
IX. Ayurvedic Perspective on Pyuria (Mutrakrichra β Dysuria)
πΉ Dosha Involvement:
- Vataja Mutrakrichra: Scanty urine, pain, dryness
- Pittaja Mutrakrichra: Burning sensation, yellow urine
- Kaphaja Mutrakrichra: Mucus in urine, heaviness
πΉ Ayurvedic Herbs & Remedies
| Herb/Remedy | Action |
|---|---|
| Gokshura (Tribulus terrestris) | Diuretic, Anti-inflammatory |
| Punarnava (Boerhavia diffusa) | Reduces fluid retention |
| Varun (Crataeva nurvala) | Bladder tonic, stone prevention |
| Chandraprabha Vati | Urinary antiseptic |
| Coconut water, Barley water | Soothes urinary tract |