Urinary Tract Infection: Symptoms, Signs, and Management
Clinical Presentation
Uncomplicated cystitis is diagnosed clinically when a patient presents with dysuria plus at least one of the following: urinary frequency, urgency, suprapubic pain, or new/worsening incontinence—without fever or flank pain. 1
Key Symptoms
- Dysuria (painful urination) is the hallmark symptom and most diagnostic finding 2, 3, 4
- Urinary frequency and urgency are highly specific when combined with dysuria 2, 5, 4
- Suprapubic discomfort or pain localizes the infection to the bladder 1, 2
- Hematuria may be present but is nonspecific 2, 4
- Absence of vaginal discharge increases the likelihood of UTI (vaginal discharge suggests alternative diagnosis like vaginitis or cervicitis) 2, 4, 6
Signs of Complicated Infection (Pyelonephritis)
- Fever >37.8°C (100°F) indicates upper tract involvement 1, 5
- Costovertebral angle tenderness or flank pain suggests kidney infection 1, 5
- Systemic symptoms including rigors, shaking chills, or clear-cut delirium warrant immediate evaluation for pyelonephritis or urosepsis 1, 7
Special Considerations in Elderly Patients
- Atypical presentations are common: altered mental status, functional decline, falls, fatigue, or new confusion may be the only manifestations 1, 8
- Nonspecific symptoms alone (malaise, decreased appetite, incontinence without dysuria) should NOT trigger UTI treatment without localizing urinary symptoms 1
Diagnostic Approach
In women with typical symptoms (dysuria, frequency, urgency) and no vaginal discharge, clinical diagnosis alone is sufficiently accurate—no urinalysis or culture is required for uncomplicated cases. 3, 4
When to Perform Urinalysis
- Atypical presentations or diagnostic uncertainty 1
- Elderly or frail patients where symptoms may be nonspecific 1, 8
- Suspected pyelonephritis or complicated infection 1
Interpreting Urinalysis
- Negative nitrite AND negative leukocyte esterase together effectively rule out UTI in most patients (though specificity is lower in elderly, 20-70%) 1, 7
- Pyuria alone has poor positive predictive value because it indicates genitourinary inflammation from many noninfectious causes (incontinence, irritation, stones) 1
- Bacteriuria is more specific than pyuria for actual infection 4
- The absence of pyuria makes UTI unlikely and should prompt evaluation for alternative diagnoses 1, 5
When to Order Urine Culture
Urine culture is NOT needed for simple uncomplicated cystitis in healthy nonpregnant women. 1, 3
Culture IS indicated for:
- Suspected pyelonephritis (fever, flank pain) 1, 7
- Recurrent infections or treatment failure 1, 3
- History of resistant organisms 3
- All men with UTI symptoms 3
- Elderly patients (≥65 years) even with uncomplicated presentation 3
- Pregnant women (culture is gold standard) 4
- Suspected urosepsis (obtain culture before antibiotics, along with blood cultures) 1, 7
Critical Pitfall to Avoid
Do NOT treat asymptomatic bacteriuria (positive culture without symptoms)—this is extremely common in elderly patients (15-50% prevalence) and catheterized patients (nearly 100%), and treatment causes harm without benefit through unnecessary antibiotic exposure and resistance development. 1
Management
First-Line Antibiotic Therapy for Uncomplicated Cystitis
The optimal first-line choices are nitrofurantoin (5 days), fosfomycin (single 3g dose), or trimethoprim-sulfamethoxazole (3 days)—selected based on local resistance patterns and patient factors. 7, 8, 3
Specific Regimens:
- Nitrofurantoin 100 mg twice daily for 5 days 8, 3, 4
- Fosfomycin 3g single dose (particularly advantageous with renal impairment) 7, 8, 3
- Trimethoprim 100 mg twice daily for 3 days 3
- Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (only if local resistance <20%) 9, 3, 4
Treatment Duration
Three-day therapy is superior to single-dose treatment for eradicating infection and preventing relapse, while identifying patients with occult upper tract disease who fail short-course therapy. 2
Antibiotics to AVOID as First-Line
- Fluoroquinolones should be reserved for complicated infections only due to antimicrobial stewardship concerns, increasing resistance, and significant adverse effects (especially in elderly) 7, 8, 3
- Amoxicillin-clavulanate is explicitly NOT recommended for empiric UTI treatment 7
- Beta-lactams have increasing resistance and are not preferred first-line agents 4
Treatment for Men
All men with lower UTI symptoms require antibiotics for 7 days (longer than women due to higher risk of prostatic involvement), with urine culture to guide therapy. 3
First-line options:
- Trimethoprim, trimethoprim-sulfamethoxazole, or nitrofurantoin for 7 days 3
- Consider urethritis and prostatitis in the differential diagnosis 3, 6
Pyelonephritis Management
- Obtain urine culture and blood cultures before starting antibiotics 1, 7
- Fluoroquinolones remain the oral mainstay for pyelonephritis despite resistance concerns, as other cystitis agents achieve inadequate tissue levels 5
- Hospitalization and IV antibiotics may be needed for severe systemic symptoms, inability to tolerate oral intake, or suspected urosepsis 5
Symptomatic Treatment
Phenazopyridine (urinary analgesic) provides symptomatic relief of dysuria, burning, and urgency but should not exceed 2 days and does not replace definitive antibiotic treatment. 10
NSAIDs for symptomatic relief may be considered, and delayed antibiotic approach is reasonable in low-risk patients given the low complication rate. 3
Special Populations
Elderly/Frail Patients
- Same antibiotics and durations as younger adults unless complicating factors present 1, 3
- Always obtain urine culture in patients ≥65 years to adjust therapy based on susceptibilities 3
- Monitor for adverse drug reactions given polypharmacy and altered pharmacokinetics 1
- Assess renal function before prescribing (many elderly have decreased clearance) 1, 8
- Avoid fluoroquinolones for prophylaxis in this population 1
Catheterized Patients
- Change catheter before specimen collection if long-term catheter present and urosepsis suspected 1
- Asymptomatic bacteriuria is universal with chronic catheters—do not treat without symptoms 1
Follow-Up and Reassessment
- Reassess within 48-72 hours to ensure clinical improvement 8
- Tailor antibiotics once culture results available to narrowest spectrum agent 8
- Treatment failure suggests possible upper tract involvement, resistant organism, or alternative diagnosis 2, 3
Prevention of Recurrent UTI
- Increased fluid intake 3
- Cranberry products have evidence for prevention 3
- Methenamine hippurate is an antimicrobial-sparing option 3
- Antibiotic prophylaxis is effective but carries risks of adverse effects and resistance development 3
- Probiotics and D-mannose have insufficient evidence for clear recommendations 1