Pyuria

Pyuria
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Overview
Definition
Classification
Pyuria Differential Diagnosis
Treatment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sadaf Sharfaei M.D.[2]

To view a comprehensive algorithm of common findings of urine composition and urine output, click here

Overview

Pyuria is a condition in which urine contains 10 or more white cells/mm³. Gram stain and leukocyte esterase might be positive. Pyuria might be a sign of a bacterial or non bacterial urinary tract infection, genitourinary abnormalities, inflammatory disorders, and systemic diseases. Pyuria may be classified into sterile pyuria or bacteriuria. Treatment is not required for pyuria. However, underlying diseases must be treated.

Definition

Pyuria is a condition in which urine contains pus. Definition of pyuria is as follow:

• Presence of 10 or more white cells/mm³ in a urine specimen
• Positive result on Gram’s stain of an unspun urine specimen
• Positive leukocyte esterase on urinary dipstick test

Pyuria might be a sign of a bacterial or non bacterial urinary tract infection.

Classification

Pyuria may be classified based on the presence of detectable infection as shown below:

Classification of pyuria
Group	Cell count	Bacteria	Etiology
Sterile pyuria	↑	-	Might have infectious or non-infectious etiologies.
Bacteriuria	↑	Positive bacterial colony >1000 colony-forming units/ml	Mostly have infectious etiologies.

Pyuria Differential Diagnosis

Differentiating the diseases that can cause pyuria:

To review differential diagnosis of sterile pyuria, click here.

Category	Disease			Clinical manifestations									Para−clinical findings								Gold standard for diagnosis	Associated findings
				Symptoms							Physical examination
													Lab Findings							Imaging
				Pain	Fever	N/V	Urinary symptoms				BP	Other	CBC	Electrolytes	Urinalysis
							Dysuria	Frequency	Urgency	Gross hematuria					Cell	Cast	Bacteriuria	Culture	Other
Infectious diseases	UTI	Bacterial	Asymptomatic bacteriuria	−	−	−	−	−	−	−	Nl	−	Nl	Nl	±	−	+	−	NA	NA	Urinalysis	Increased risk in pregnancy Must be treated prior to an invasive urologic procedure
			Cystitis	−	−	−	+	+	+	−	Nl	−	Nl	Nl	+	−	+	+	Nitrite + Leukocyte esterase +	NA	Urinalysis	NA
			Pyelonephritis	+	+	+	+	+	+	−	Nl	−	Leukocytosis	Nl	+	WBC cast	+	+	Nitrite + Leukocyte esterase +	NA	Clinical manifestation + urinalysis	NA
		Viral		−	−	+	+	+	+	±	Nl	−	Nl	Nl	+	−	−	−	NA	NA	PCR viral load	Increased risk in immunosuppressed kidney transplant patients CMV, EBV, BK virus, adenovirus might be seen
		Tuberculosis		−	±	−	+	+	+	+	Nl	−	Nl	Nl	±	−	−	Positive mycobacterial urine culture	Microscopic hematuria	Pulmonary TB on chest CT	Urine mycobacterial PCR	Past history of pulmonary TB
		Fungal		−	−	−	+	+	−	−	Nl	−	Nl	Nl	±	−	−	+ after several weeks of follow up	NA	Hydronephrosis on ultrasound	Urine culture	Increased risk in patients with long−term foley catheters Candida as the most prevalent fungus
		STD	Chlamydia	Chronic pelvic pain	−	−	+	+	−	−	Nl	Abdominal tenderness Adnexal motion tenderness	Nl	Nl	+	−	−	+	NA	NA	PCR	Females might have concurrent chlamydial cervicitis Must be considered in young, sexually active males
			Gonococcus	Chronic pelvic pain	−	−	+	+	−	−	Nl	Abdominal tenderness Adnexal motion tenderness	Nl	Nl	+	−	−	+ High false negative result	Intracellular gram−negative diplococci on gram stain	NA	Nucleic acid amplification testing (NAAT)	Females might have concurrent cervical gonococcal infection Must be considered in young, sexually active males
			Ureaplasma urealyticum	−	−	−	+	+	−	−	Nl	−	Nl	Nl	+	−	−	−	Gram stain −	NA	PCR	Associated with complications of pregnancy
			Herpes simplex virus	+	+	−	+	+	−	−	Nl	Painful genital ulcers Tender local inguinal lymphadenopathy Acute urinary retention Loss of sacral sensation	Nl	Nl	+	−	−	Viral culture +	NA	NA	Clinical manifestation + PCR	Associated with extragenital complications, like aseptic meningitis High risk of recurrence
			Herpes zoster	−	−	−	+	+	−	−	Nl	Rash Acute neuritis	Nl	Nl	+	−	−	−	Microscopic hematuria	NA	Clinical manifestation + PCR	Associated with lumbosacral dermatome involvement
			HPV	−	−	−	+	−	−	−	Nl	Genital wart Cancerous lesions of the genitalia	Nl	Nl	+	−	−	−	NA	NA	Clinical manifestation + PCR	Associated with bladder carcinoma Prevented by HPV vaccination
			HIV	−	+	+	+	+	−	−	Nl	Painful mucocutaneous ulceration Lymphadenopathy Aseptic meningitis  Diarrhea Weight loss	Leukopenia	Nl	+	−	−	−	NA	NA	Combination antigen/antibody immunoassay + PCR HIV viral load test	Might be gone to chronic HIV infection with or without evidence of the acquired immunodeficiency syndrome (AIDS) Associated with acute interstitial nephritis
		Prostatitis		Pelvic or perineal pain	+	+	+	+	+	−	Nl or ↑	Dribbling of urine Firm and tender prostate	Leukocytosis	Nl	+	−	±	+	Cloudy urine Positive gram stain	NA	Clinical manifestation + urinalysis	Increased risk of bacteremia, prostatic abscess, and metastatic infection Might be acute or chronic infection
	Balanitis			Penile pain	+	−	+	+	+	−	Nl	Pruritus Erythematous lesions on the glans and/or the foreskin	Nl	Nl	+	−	±	−	NA	NA	Clinical manifestation	Associated with reactive arthritis
	Appendicitis			Right lower abdominal pain	+	+	+	+	+	−	Nl	Right lower abdominal tenderness	Leukocytosis	Nl	+	−	−	−	Urine specific gravity >1.020	Enlarged appendiceal diameter on CT scan or ultrasound	Clinical manifestation	NA
Category	Disease			Pain	Fever	N/V	Dysuria	Frequency	Urgency	Gross hematuria	BP	Other PE	CBC	Electrolytes	Cell	Cast	Bacteriuria	Culture	Other UA findings	Imaging	Gold standard for diagnosis	Associated findings
Non−infectious diseases	Urinary tract disorders	Urinary catheterization		−	−	−	+	+	−	−	Nl	−	Leukocytosis ±	Nl	+	−	+	+	Leukocyte esterase ±	−	Clinical manifestation + urinalysis	Predicting UTI in children who required clean intermittent catheterization by routine urinalysis
		Urinary tract stone		Colicky pain	−	+	+	+	+	±	Nl	−	Nl	Nl	+	−	−	−	Microscopic hematuria	Visible stone on CT scan	Clinical manifestation	Might cause renal obstruction
		Urinary tract neoplasm		+	+	+	+	+	+	+	Nl	−	Nl	Nl	+	−	−	−	Microscopic hematuria	Visible tumor on CT scan	Cystoscopy  + biopsy	Associated with non−muscle−invasive bladder cancer (NMIBC)
		Urinary fistula		−	−	−	+	+	−	−	Nl	Urinary incontinence	Nl	Nl	+	−	−	−	NA	Fistula on cystoscopy or IVP	Physical examination	History of recent surgery
		Interstitial cystitis		Chronic bladder pain	−	−	+	+	+	−	Nl	Abdominal tenderness	Nl	Nl	+	−	−	−	NA	NA	Clinical manifestation	Associated with other chronic pain syndromes
		Vesicoureteral reflux		+	−	−	+	−	−	−	Nl	Oliguria	Nl	Nl	+	−	−	−			Imaging
		Hydronephrosis		−	−	−	+	−	−	−	Nl	Oliguria	Nl	Nl	+	−	−	−			Imaging
	Renal diseases	Polycystic kidney disease		Flank or back pain	−	−	+	+	−	+	↑	Polyuria Nocturia	Nl	Nl	+	−	−	−	Hypocitraturia Hyperuricemia Hyperoxaluria Low urine pH Microscopic hematuria Proteinuria <1 g/day	Multiple cysts on ultrasound	Imaging
		Renal vein thrombosis		Flank pain	+	+	+	+	+	+	Nl or ↑	Might be asymptomatic Signs of acute renal failure	Leukocytosis	Hyperkalemia	+	−	−	−	Proteinuria Microscopic hematuria	Thrombosis on CT scan	Renal venography	Increased risk in nephrotic syndrome and hypercoagulable state
		Interstitial nephritis		Lower back pain	−	−	+	+	−	−	Nl or ↑	Rash Weight loss Oliguria	Eosinophilia	Hyperkalemia Isosthenuria	+	+	−	−	Proteinuria Eosinophiluria	Nl	Clinical manifestation + urinalysis	Associated with medications, particularly antibiotics
		IgA nephropathy		−	−	−	−	−	−	+	Nl or ↑	Might be asymptomatic	Nl	Nl	+	−	−	−	Proteinuria Microscopic hematuria	Nl	Biopsy	History of upper respiratory infection
		Renal transplant rejection		Flank pain	+	+	+	+	+	+	↑	Might be asymptomatic Oliguria	Leukocytosis	Nl	+	+	−	−	Proteinuria Microscopic hematuria	Increased graft size on ultrasound	Renal allograft biopsy	Acute rise in the serum creatinine History of transplant
	Disease			Pain	Fever	N/V	Dysuria	Frequency	Urgency	Gross hematuria	BP	Other PE	CBC	Electrolytes	Cell	Cast	Bacteriuria	Culture	Other UA findings	Imaging	Gold standard for diagnosis	Associated findings
	Systemic disease	Diabetic nephropathy		−	−	−	−	−	−	±	↑	Might be asymptomatic	Nl	Nl	+	−	−	−	Albuminuria Microscopic hematuria	Nl	Clinical manifestation + laboratory tests	History of retinopathy and neuropathy Slow and progressive renal failure
		Lupus nephritis		−	+	−	+	+	+	+	↑	Rash Oral ulcer Arthritis	Pancytopenia	Nl	+	+	−	−	Hematuria Proteinuria	Enlarged kidneys on CT scan	Biopsy	Abnormal results of specific serologic tests
		Sjögren’s syndrome		−	−	−	+	+	−	−	↑	Dryness of all mucous membranes	Pancytopenia	Nl	+	+	−	−	Hematuria Proteinuria	Abnormal diffuse fat tissue deposition and diffuse punctate calcification on parotid gland CT scan	Clinical manifestation + laboratory tests	Abnormal results of specific serologic tests
		Kawasaki's disease		−	+	−	+	+	+	−	Nl	Rash Irritability Desquamation of skin and mucous membranes	Normocytic normochromic anemia Thrombocytosis Leukocytosis	Hyponatremia	+	−	−	−	−	Vessels involvement on angiography	Clinical manifestation	Associated with multiple organ involvement including heart
	Medication/toxin	Analgesic nephropathy		Flank pain	+	+	+	+	+	+	↑	Chronic headache Low back pain	Eosinophilia	Hyperkalemia Isosthenuria	+	+	−	−	Proteinuria Eosinophiluria	Renal impairment on CT scan	Imaging	Characterized by papillary necrosis and chronic interstitial nephritis Caused by the chronic use of analgesic agents
		Contrast−induced nephropathy		+	−	+	+	−	−	−	Nl	Oliguria	Nl	Hyperkalemia Acidosis Hyperphosphatemia	+	+	−	−	Fractional sodium excretion (FENa) <1%	NA	Clinical manifestation + exclusion of other causes of AKI	Associated with reversible type of acute kidney injury Acute increase in the serum creatinine
Category	Disease			Pain	Fever	N/V	Dysuria	Frequency	Urgency	Gross hematuria	BP	Other PE	CBC	Electrolytes	Cell	Cast	Bacteriuria	Culture	Other UA findings	Imaging	Gold standard for diagnosis	Associated findings

Treatment

• Sterile pyuria

• Pathogen-directed antimicrobial therapy

• Renal Tuberculosis

• Preferred regimen: (Isoniazid 300 mg PO qd for 2 months AND Rifampicin 450-600 mg qd for 2 months AND Ethambutol 15-25 mg/kg PO qd for 2 months AND Pyrazinamide 1500 mg for 2 months) THEN (Isoniazid 300 mg PO qd for 4-6 months AND Rifampicin 450-600 mg qd for 4-6 months)

• Gonorrhea

• Preferred regimen: Ceftriaxone 250 mg IM in a single dose THEN (Azithromycin 1 g PO in a single dose OR Doxycycline 100 mg PO bid for 7 days)

• Chlamydia

• Preferred regimen: Azithromycin 1 g PO in single dose OR Doxycycline 100 mg PO bid for 7 days
• Alternative regimen: Erythromycin base 500 mg PO qid for 7 days

• Mycoplasma and Ureaplasma

• Preferred regimen: Azithromycin OR Levofloxacin OR Moxifloxacin

• Genital herpes

• Preferred regimen: Acyclovir 400 mg PO tid for 7–10 days or Acyclovir 200 mg PO five times a day for 7–10 days OR Famciclovir 250 mg PO tid for 7–10 days OR Valacyclovir 1 g PO bid for 7 days

• Trichomoniasis

• Preferred regimen: Metronidazole 2 g PO in a single dose OR Tinidazole 2 g PO in a single dose

Note: Treat patient’s sex partner if trichomoniasis is diagnosed in patient.

• Fungal infections

• Preferred regimen, Candida albicans: Fluconazole 100 mg PO qd for 2-5 days
• Preferred regimen, non-albicans Candida: Amphotericin B 0.1 mg/kg/day IV for 2-5 days OR Amphotericin B bladder irrigation 5-50 mg/L of sterile water qd for 2-5 days

• Schistosomiasis

• Preferred regimen: Praziquantel 20 mg/kg PO bid for 1–2 days