What is the treatment for elevated C-Reactive Protein (CRP) levels in children?

Treatment for Elevated C-Reactive Protein (CRP) in Children

The treatment for elevated C-Reactive Protein (CRP) in children should not target the CRP itself, but rather identify and treat the underlying cause of inflammation, as CRP is a marker rather than a disease. 1

Understanding CRP in Children

CRP is an inflammatory biomarker produced by the liver in response to inflammation. In children:

• CRP levels correlate with obesity in children as young as 3 years of age 2
• CRP elevations are associated with cardiovascular risk factors including adiposity and blood pressure 2
• CRP values have relatively stable levels during the day and from day to day 1

Diagnostic Approach to Elevated CRP

When encountering elevated CRP in a child, follow this algorithm:

1. Interpret CRP values in clinical context:

   • <1.0 mg/L: Low risk/minimal inflammation
   • 1.0-3.0 mg/L: Average risk/moderate inflammation

   • 3.0 mg/L: High risk/significant inflammation

   • 10 mg/L: Suggests acute infection or significant inflammation 1

2. Consider timing since symptom onset:

   • In patients presenting ≥72 hours after symptom onset, estimated CRP velocity (eCRPv) >1.08 mg/L/h strongly predicts bacterial infection (aOR = 5.5) 3
   • CRP >40 mg/L has high specificity (88%) for bacterial versus viral infection 4

3. Evaluate for specific conditions based on CRP level:

   • Very high CRP (>100 mg/L):
     • In first 3 days of life: Often non-infectious causes (81%) 5
     • After day 4 of life: Likely infectious causes (87%), especially in preterm infants 5
   • CRP ≥10 mg/dL (100 mg/L): Consider MIS-C if fever and SARS-CoV-2 exposure 2

Treatment Approaches Based on Underlying Cause

1. Infectious Causes

• Bacterial infections: Appropriate antibiotics based on suspected source and local resistance patterns
• MIS-C: For CRP ≥10 mg/dL with fever and suspected SARS-CoV-2 exposure, consider hospital admission and treatment per American College of Rheumatology guidelines 2

2. Inflammatory Bowel Disease

• If suspected, obtain fecal calprotectin (more sensitive than CRP) 1
• Treatment includes conventional glucocorticosteroids, immunomodulators, or biologic agents 1

3. Obesity-Related Inflammation

• Weight management interventions:
  • Dietary modifications (Mediterranean diet has been shown to decrease CRP) 2
  • Increased physical activity 1
  • Lifestyle changes 2

4. Cardiovascular Risk

• The American Heart Association states there is currently no clinical role for measuring CRP routinely in children when assessing cardiovascular disease risk factors 1
• Weight loss by lifestyle change or nutritional modifications can produce a decrease in CRP 2

Monitoring Response to Treatment

• Serial CRP measurements are more valuable than single values 1
• Consider combining CRP with ESR to distinguish between acute and chronic inflammation:
  • Elevated CRP + Normal ESR = Acute inflammation
  • Normal CRP + Elevated ESR = Chronic inflammation
  • Elevated CRP + Elevated ESR = Active inflammation 1

Common Pitfalls to Avoid

1. Treating CRP itself rather than the underlying cause 1
2. Overreliance on single CRP values instead of serial measurements 1
3. Ignoring clinical context when interpreting CRP values 1
4. Routine screening in otherwise healthy children is not recommended 1
5. Assuming low CRP rules out bacterial infection - it does not 4
6. Assuming all high CRP indicates infection - non-infectious causes like obesity can elevate CRP 2

Remember that CRP is a downstream marker of inflammation with multiple effects, including complement binding and augmentation of expression of adhesion molecules 2. The goal of treatment should always be to address the underlying inflammatory process rather than the biomarker itself.