What is the diagnosis and treatment for a 39-year-old female on birth control, presenting with dysuria (painful urination), hematuria (blood in urine), and a passed clot, with urinalysis results showing significant leukocytosis (elevated white blood cells), nitrite positive, and ketonuria (ketones in urine), but no fever or back pain?

Diagnosis: Acute Hemorrhagic Cystitis (Uncomplicated Urinary Tract Infection)

This patient has acute hemorrhagic cystitis requiring immediate empiric antibiotic treatment based on her classic presentation of dysuria, urgency, hematuria with clot passage, and positive urinalysis showing significant leukocyturia (70 WBC) and nitrite positivity. 1

Clinical Reasoning

The diagnosis is straightforward based on the combination of:

• Acute onset urinary symptoms (dysuria, urgency, frequency) occurring over 3 days, which have >90% accuracy for UTI when present together 1, 2
• Gross hematuria with clot passage (0.5cm clot), which raises the post-test probability of bacterial cystitis to 75.8% and is present in approximately 50% of acute cystitis cases 3, 2
• Positive urinalysis findings: Leukocytes 70 (significantly exceeds the ≥10 WBC/HPF threshold), nitrite positive (98-100% specificity for gram-negative bacteria), and blood 200 1, 4
• Absence of upper tract involvement: No fever, no back pain, no systemic symptoms—this rules out pyelonephritis 5

The combination of positive leukocyte esterase with positive nitrite achieves 93% sensitivity and 96% specificity for culture-proven UTI. 1

Immediate Management Algorithm

Step 1: Obtain Urine Culture Before Starting Antibiotics

• Collect urine culture with antimicrobial susceptibility testing immediately before initiating treatment, as the presence of gross hematuria with clot passage warrants culture documentation 1
• Use midstream clean-catch technique and process within 1 hour at room temperature or 4 hours if refrigerated 1

Step 2: Initiate Empiric Antibiotic Treatment

First-line treatment options (choose one):

• Nitrofurantoin 100 mg orally twice daily for 5-7 days (preferred due to high effectiveness and minimal resistance) 1, 5
• Fosfomycin 3 grams orally as a single dose (excellent alternative with low resistance rates) 1
• Trimethoprim-sulfamethoxazole 160/800 mg orally twice daily for 3 days (only if local resistance <20% and no recent exposure) 1

Do NOT delay antibiotic initiation while awaiting culture results in symptomatic patients with positive urinalysis. 1

Step 3: Address the Hematuria

While gross hematuria is common in acute bacterial cystitis (occurring in ~50% of cases), the passage of a 0.5cm clot requires additional consideration:

• The hematuria in this context is likely secondary to severe bladder mucosal inflammation from infection and should resolve with antibiotic treatment 3, 2
• If hematuria persists after successful UTI treatment (confirmed by symptom resolution and negative follow-up culture if obtained), refer for urologic evaluation per American College of Physicians guidelines, as any episode of gross hematuria warrants consideration of underlying pathology 6
• No immediate imaging is indicated given the clear infectious etiology and absence of risk factors for complicated UTI 1

Critical Pitfalls to Avoid

• Do not attribute the hematuria solely to birth control pills without treating the documented infection—the positive nitrite and significant pyuria confirm bacterial infection requiring treatment 1
• Do not delay treatment to await culture results—empiric therapy is indicated immediately in symptomatic patients with positive urinalysis 1
• Do not use fluoroquinolones as first-line therapy for uncomplicated cystitis due to resistance concerns and adverse effect profile; reserve for complicated infections or pyelonephritis 1, 5
• Do not assume this is asymptomatic bacteriuria—the patient has clear acute urinary symptoms requiring treatment 1

Follow-Up Requirements

• Reassess clinical response within 48-72 hours: Symptoms should improve significantly within 48 hours of appropriate antibiotic therapy 1, 5
• If symptoms persist or worsen despite treatment, consider imaging to evaluate for complications (stones, obstruction) or adjust antibiotics based on culture sensitivities 1, 5
• No routine follow-up culture is needed if symptoms resolve completely with treatment 1
• If hematuria persists beyond UTI resolution, refer to urology for cystoscopy and imaging evaluation per hematuria guidelines 6

Special Considerations for This Patient

• Birth control use does not contraindicate standard UTI treatment and does not explain the acute infectious presentation 1
• Ketones 1.5 in urinalysis likely reflect decreased oral intake due to dysuria symptoms and nausea from infection; ensure adequate hydration during treatment 1
• The absence of fever and back pain effectively rules out pyelonephritis, allowing for outpatient oral antibiotic management 5