Increasing CRP in an Elderly Woman with UTI and Cervicitis on Antimicrobials
Most Likely Cause
The increasing CRP despite antimicrobial therapy most likely indicates treatment failure due to antimicrobial-resistant organisms, inadequate source control of the cervicitis, or development of a complication such as ascending infection or abscess formation. 1, 2
Diagnostic Reasoning
Treatment Failure Considerations
- Antimicrobial resistance is a critical concern in elderly patients with UTI, with resistance rates varying significantly by age group and prior antibiotic exposure 3, 4
- Elderly patients (65-84 years) show lower susceptibility to commonly prescribed antibiotics compared to younger adults, with only 35% susceptibility to amoxicillin in this age group versus 81% in the oldest old 3
- Prior antimicrobial exposure within 12 months significantly increases the risk of resistant uropathogens, making initial empiric therapy potentially inadequate 4
Cervicitis as a Confounding Factor
- Cervicitis represents a separate infectious focus that may not be adequately addressed by antibiotics chosen primarily for UTI coverage 1
- The Pap smear procedure itself can cause transient inflammation and minor trauma, but would not typically cause sustained CRP elevation if performed appropriately 5
- Cervicitis requires specific consideration of sexually transmitted pathogens (Chlamydia, Gonorrhea) that may not be covered by standard UTI regimens 1
Complications to Consider
- Elderly patients are at higher risk for serious complications including bacteremia, ascending pyelonephritis, and abscess formation 6, 7
- Urosepsis must be excluded if systemic signs are present (fever >100°F, shaking chills, hypotension) 8
- Mortality from infections is significantly higher in elderly patients due to frequent complications 7
Immediate Management Algorithm
Step 1: Assess for Complications
- Obtain blood cultures immediately if fever, rigors, or hemodynamic instability are present 8
- Evaluate for costovertebral angle tenderness suggesting ascending pyelonephritis 8, 2
- Check renal function as elderly patients have approximately 40% decline in renal function by age 70 8
Step 2: Obtain Cultures Before Changing Therapy
- Urine culture with susceptibility testing is mandatory in elderly patients to guide targeted therapy 8, 2
- Consider cervical cultures for Chlamydia and Gonorrhea if not already obtained 1
- Blood cultures if systemic signs present 8
Step 3: Reassess Antimicrobial Coverage
- Review current antimicrobial regimen for adequacy against both UTI pathogens and cervicitis organisms 1, 2
- If initial therapy was fluoroquinolone or TMP-SMX, resistance is increasingly common in elderly patients 3, 4
- Consider broadening coverage empirically while awaiting culture results if patient is clinically deteriorating 7
Step 4: Evaluate for Inadequate Source Control
- Cervicitis may require different antimicrobial coverage than UTI alone 1
- Consider pelvic examination to assess for abscess formation or other complications 1
- Evaluate for urinary retention, obstruction, or other anatomic factors complicating UTI treatment 1
Common Pitfalls to Avoid
- Do not assume the Pap smear caused the rising CRP - while minor trauma can occur, sustained inflammatory response suggests ongoing infection 5
- Do not continue ineffective antibiotics while waiting for culture results if the patient is clinically worsening 7, 4
- Do not overlook the dual infectious foci - both UTI and cervicitis require appropriate coverage 1
- Elderly patients often present with atypical symptoms - absence of fever does not exclude serious infection as fever response is often blunted 2, 7