Dysuria, Urinary Frequency, and Urgency: MCCQE1 Approach

Introduction

Lower urinary tract symptoms (LUTS) such as dysuria (painful urination), frequency, and urgency are among the most common reasons for primary care visits in Canada. For MCCQE1 preparation, it is crucial to adopt a structured approach to differentiate between infectious etiologies (like Cystitis, Pyelonephritis, Urethritis) and non-infectious causes.

This guide focuses on the Medical Expert and Health Advocate CanMEDS roles, emphasizing appropriate resource stewardship (Choosing Wisely Canada) and evidence-based management.

Definitions and Pathophysiology

Understanding the terminology is the first step in clinical reasoning.

• Dysuria: Pain, burning, or discomfort during urination.
• Urgency: A sudden, compelling desire to pass urine that is difficult to defer.
• Frequency: Voiding at abnormally brief intervals (often defined as >8 times per waking day).
• Pyuria: Presence of white blood cells (WBCs) in the urine (usually >10 WBCs/mm³ or >5-10 WBCs/hpf).
• Sterile Pyuria: Presence of WBCs in urine with a negative standard bacterial culture.

Differential Diagnosis

The differential diagnosis for these symptoms is broad. Use the following tabs to categorize etiologies based on the clinical picture.

Clinical Evaluation

Follow this step-by-step approach to evaluate a patient presenting with dysuria, frequency, or urgency.

Diagnostic Interpretation: Urinalysis vs. Culture

Sterile Pyuria

A classic MCCQE1 topic is the patient with pyuria but negative bacterial cultures.

Differential for Sterile Pyuria:

• Stones
• Tumor (Bladder cancer)
• Interstitial Cystitis
• Renal Tuberculosis (Consider in immigrants from endemic areas)
• Urethritis (Chlamydia/Gonorrhea often don’t grow on standard culture)
• Partially treated UTI

Canadian Guidelines for Management

1. Uncomplicated Cystitis (Non-pregnant women)

Diagnosis: Symptoms alone (dysuria, frequency, urgency) without vaginal discharge or fever often suffice. Urine culture is not routinely indicated.

First-line Treatment Options (Canada):

• Nitrofurantoin: 100 mg PO BID x 5 days (Avoid if eGFR <30 mL/min).
• Trimethoprim-Sulfamethoxazole (TMP-SMX): 1 DS tab PO BID x 3 days (Avoid if local resistance >20%).
• Fosfomycin: 3g PO sachet x 1 dose (Lower efficacy than Nitrofurantoin).

2. Acute Pyelonephritis

Diagnosis: Fever, flank pain, CVA tenderness, nausea/vomiting. Urine culture is mandatory.

Outpatient Management:

• Ciprofloxacin: 500 mg PO BID x 7 days (if community resistance <10%).
• Ceftriaxone: 1g IV x 1 dose, followed by oral antibiotics (if fluoroquinolone resistance is suspected or unknown).

3. Asymptomatic Bacteriuria

Definition: Significant bacterial count in urine without symptoms.

Who to Treat:

1. Pregnant women: Screen at 12–16 weeks. Treat to prevent pyelonephritis and preterm labour.
2. Patients undergoing invasive urologic procedures where mucosal bleeding is anticipated.

Who NOT to Treat (Choosing Wisely Canada):

1. Non-pregnant women.
2. Diabetics.
3. Elderly institutionalized patients.
4. Patients with indwelling catheters (unless systemic signs of infection).

4. Recurrent UTIs

Defined as $\ge$2 infections in 6 months or $\ge$3 in 1 year.

• Management: Behavioural modification, post-coital prophylaxis, or self-start therapy.

Comparison of Clinical Features

Key Points to Remember for MCCQE1

• Imaging: Renal ultrasound is indicated for pyelonephritis if the patient is male, diabetic, immunosuppressed, has recurrent infections, or fails to improve after 48-72 hours of antibiotics.
• Men: A UTI in a man is generally considered complicated. Always investigate for structural abnormalities (e.g., BPH).
• Pediatrics: Febrile UTI in children <2 years requires ultrasound to rule out vesicoureteral reflux (VUR).
• Elderly: Acute confusion (delirium) may be the only sign of urosepsis, but do not attribute delirium to a UTI solely based on a positive dipstick in the absence of other symptoms (asymptomatic bacteriuria is common).

Sample Question

Stem: A 24-year-old female presents to her family physician with a 2-day history of dysuria, urinary frequency, and suprapubic pain. She denies fever, chills, flank pain, or vaginal discharge. She is sexually active and uses condoms for contraception. Her last menstrual period was 2 weeks ago. She has no significant past medical history and takes no medications. Vital signs are: BP 110/70 mmHg, HR 78 bpm, Temp 37.0°C. Abdominal examination reveals mild suprapubic tenderness but no costovertebral angle tenderness.

Which one of the following is the most appropriate next step in management?

Options:

• A. Order a renal ultrasound
• B. Perform a pelvic examination and obtain cervical swabs
• C. Prescribe Nitrofurantoin 100 mg BID for 5 days without urine culture
• D. Send urine for culture and sensitivity and await results before treating
• E. Prescribe Ciprofloxacin 500 mg BID for 3 days

Explanation

The correct answer is:

• C. Prescribe Nitrofurantoin 100 mg BID for 5 days without urine culture

Detailed Explanation:

• Option C is correct: This patient presents with classic symptoms of uncomplicated cystitis (dysuria, frequency, suprapubic pain) without “red flags” suggesting pyelonephritis (fever, flank pain) or vaginitis/STI (vaginal discharge). In non-pregnant, pre-menopausal women with typical symptoms of uncomplicated cystitis, Canadian guidelines recommend empiric treatment without a pre-treatment urine culture. Nitrofurantoin is a first-line agent.
• Option A is incorrect: Imaging is not indicated for a first episode of uncomplicated cystitis. It is reserved for complicated cases, recurrent infections, or failure to respond to therapy.
• Option B is incorrect: In the absence of vaginal symptoms (discharge, itch) or high-risk history, a pelvic exam is not routinely required for uncomplicated cystitis.
• Option D is incorrect: While culture is the gold standard, it is not cost-effective or necessary for uncomplicated cases. Delaying treatment while awaiting results causes unnecessary morbidity.
• Option E is incorrect: Fluoroquinolones (like Ciprofloxacin) are not first-line for uncomplicated cystitis in Canada due to the risk of collateral damage (ecological adverse effects) and preserving them for more serious infections like pyelonephritis.

References

1. Anti-infective Guidelines for Community-acquired Infections. (2023). Mums Health. (The “Orange Book”).
2. Choosing Wisely Canada. Antibiotics for Urinary Tract Infections in Older People. Available at: https://choosingwiselycanada.org/ 
3. Medical Council of Canada. (2023). Objectives for the Qualifying Examination Part I.
4. RxFiles. (2023). Urinary Tract Infections: Acute Uncomplicated Cystitis.
5. Canadian Urological Association. Guidelines on the management of urinary tract infections.