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 refers to urine which contains pus. Defined as the presence of 10 or more neutrophils per high power field of unspun, voided mid-stream urine. It can be a sign of a bacterial urinary tract infection. Pyuria may be present in the septic patient, or in an older patient with pneumonia. Sterile pyuria is urine which contains white blood cells (pus) while appearing sterile by standard culture techniques. Sterile pyuria is listed as a side-effect from some medications such as paracetamol (acetaminophen).

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:

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	Edema	Other	CBC	Electrolytes	Urinalysis					Ultrasound	CT scan	Other
							Dysuria	Frequency	Urgency	Gross hematuria						Cell	Cast	Bacteriuria	Culture	Other
Infectious diseases	UTI	Bacterial	Asymptomatic bacteriuria
			Cystitis
			Pyelonephritis
		Viral
		Tuberculosis
		Fungal
		Urethritis	Chlamydia
			Gonococcus
		Prostatitis
	Balanitis
	PID
	Appendicitis
Non-infectious diseases	Urinary tract disorders	Urinary catheterization
		Urinary tract stone
		Urinary tract neoplasm
		Urinary fistula
		Interstitial cystitis
		Pelvic irradiation
	Renal diseases	Polycystic kidney disease
		Renal vein thrombosis
		Interstitial nephritis
		Analgesic nephropathy
		Papillary necrosis
	Systemic disease	Systemic lupus erythematosus
		Kawasaki's disease
		Graft versus host disease (GVHD)
Category	Disease			Pain	Fever	N/V	Dysuria	Frequency	Urgency	Gross hematuria	BP	Edema	Other	CBC	Electrolytes	Cell	Cast	Bacteriuria	Culture	Other	Ultrasound	CT scan	Other	Gold standard for diagnosis	Associated findings

Sterile Pyuria

Definition

• Sterile pyuria is defined as the persistent finding of white cells in the urine in the absence of detectable bacteria, as determined by means of aerobic laboratory techniques (on a 5% sheep-blood agar plate and MacConkey agar plate)
• Note that sterile pyuria may still be caused by an infectious agent, but the inability to detect the agent on regular urine gram-stain and culture is diagnostic of sterile pyuria.

Causes

Pyuria may have either an infectious or a non-infectious etiology:

• Infectious etiologies

• Gynecologic infection
• Urethritis due to chlamydia, Neisseria gonorrhoeae, mycoplasma, or ureaplasma
• Prostatitis
• Balanitis
• Appendicitis
• Viral infection of the lower genitourinary tract
• Genitourinary tuberculosis
• Fungal infection
• Parasitic disease such as trichomoniasis or schistosomiasis

• Non-infectious etiologies

• Current use of antibiotics
• Recently treated urinary tract infection (within past 2 weeks)
• Presence or recent use of a urinary catheter
• Recent cystoscopy or urologic endoscopy
• Urinary tract stones
• Foreign body such as surgical mesh in the urethra or a retained stent
• Urinary tract neoplasm
• Pelvic irradiation
• Urinary fistula
• Polycystic kidney
• Rejection of a renal transplant
• Renal-vein thrombosis
• Interstitial nephritis or analgesic nephropathy
• Papillary necrosis
• Interstitial cystitis
• Inflammatory disease such as systemic lupus erythematosus or Kawasaki’s disease===Antimicrobial regimen===

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