What level of Erythrocyte Sedimentation Rate (ESR) is significant in Pediatrics (Peds)?

From the Guidelines

In pediatrics, an ESR (Erythrocyte Sedimentation Rate) above 40 mm/hr is considered significant, as indicated by the American Heart Association's guidelines for the diagnosis, treatment, and long-term management of Kawasaki disease 1. For children, the following age-specific ESR ranges are typically used as upper limits of normal:

• Newborns to 6 months: 0-10 mm/hr
• 6 months to 2 years: 0-15 mm/hr
• 2 years to puberty: 0-20 mm/hr However, it's essential to note that ESR values should always be interpreted in the context of the child's clinical presentation and other laboratory findings. A single elevated ESR result is not diagnostic on its own and should prompt further investigation. When evaluating ESR results:

1. Consider the child's age, as normal ranges vary.
2. Look for trends in serial measurements rather than relying on a single value.
3. Correlate with other inflammatory markers like C-reactive protein (CRP).
4. Consider the specific clinical context, as some conditions may cause higher elevations than others. ESR is a non-specific marker of inflammation, reflecting the presence of acute-phase proteins in the blood. It measures the rate at which red blood cells settle in a tube over one hour. Increased levels of fibrinogen and other proteins cause red blood cells to stick together and settle more quickly, resulting in a higher ESR. While useful as a general indicator of inflammation, ESR should not be used in isolation for diagnosis or treatment decisions. Always combine ESR results with clinical findings and other laboratory tests for a comprehensive assessment. The American College of Rheumatology's clinical guidance for multisystem inflammatory syndrome in children associated with SARS-CoV-2 and hyperinflammation in pediatric COVID-19 also supports the use of ESR as a diagnostic tool, with elevated ESR and/or CRP being a key feature of MIS-C 1.

From the Research

Erythrocyte Sedimentation Rate (ESR) in Pediatrics

• The ESR is a valuable laboratory tool in the evaluation of infectious, inflammatory, and malignant diseases in children 2.
• A significant elevation of ESR is usually associated with serious diseases, and an ESR of ≥100 mm/hour is considered extreme 3.
• In pediatric patients, an ESR > 50 mm/hr is more likely to be associated with serious underlying disease, especially in patients presenting with limp or abdominal pain 4.
• The normal range for ESR in children is not strictly defined, but an ESR < 20 mm/hr is generally considered normal, while an ESR > 50 mm/hr may indicate significant disease 4.
• The use of IVIG therapy can falsely elevate ESR levels, making it unreliable for monitoring treatment response in patients receiving IVIG 2.

Diagnostic Categories and ESR Levels

• Infection is the most common cause of extreme elevation of ESR (≥100 mm/hr) in children, followed by connective tissue diseases, malignancy, and renal diseases 3.
• Malignancy is associated with the lowest hemoglobin value, and patients with mild infections have significantly higher mean leukocyte counts 3.
• The ESR level can be useful in evaluating disease activity and response to treatment in pediatric patients with inflammatory and infectious diseases 5.

Methodological Considerations

• Different methods for measuring ESR, such as the Westergren method and centrifugation-based methods, can yield different results, especially in pediatric populations 6.
• The centrifugation method may exceed the Westergren method by a small but significant amount in the normal range (0-20 mm/h) 6.
• The choice of method may affect the interpretation of ESR results, especially in patients with sickle cell disease, who tend to have lower ESRs due to impaired rouleau formation 6.