CRP and pericardial effusion: Acute (lasting <4–6 weeks) inflammatory pericardial syndrome to be diagnosed by ≥2 of the following: 
Pericardial chest pain* (prevalence in pediatric cases 90–95%)Pericardial rubs (prevalence in pediatric cases 30%)New widespread ST-elevation or PR depression on ECG (prevalence in pediatric cases 40–50%)Pericardial effusion (new or worsening, prevalence in pediatric cases 70–80%) Additional supporting findings:- Elevated inflammatory markers (e.g., C-reactive protein, erythrocyte sedimentation rate, and white blood cell count)- Pericardial inflammation at imaging (CT, CMR)