Extreme thrombocytosis predicts Kawasaki disease in infants

Clin Pediatr (Phila). 2006 Jun;45(5):446-52. doi: 10.1177/0009922806289621.


Infants with Kawasaki disease are at high risk of developing life-threatening coronary complications, yet may elude timely diagnosis because they often lack the full complement of classic clinical features. We retrospectively studied 26,540 children 1 year of age or less who were evaluated at a tertiary care pediatric emergency department in whom a platelet count was performed. Among those infants with fever without a source identified, 8.5% with platelet counts of 800,000 cells/mm(3) or greater had Kawasaki disease compared to 0.4% with platelet counts of less than 800,000 cells/mm(3) (likelihood ratio for Kawasaki disease was 17 [95% confidence interval, 8-34]). Because many infants present atypically, Kawasaki disease should be considered in all children of 1 year or less with prolonged fever, extreme elevation of the platelet count, and no compelling alternative diagnosis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Anemia, Iron-Deficiency / blood*
  • Cohort Studies
  • Coronary Artery Disease / diagnostic imaging*
  • Diagnosis, Differential
  • Female
  • Humans
  • Infant, Newborn
  • Likelihood Functions
  • Male
  • Mucocutaneous Lymph Node Syndrome / blood
  • Mucocutaneous Lymph Node Syndrome / diagnosis*
  • Platelet Count
  • Retrospective Studies
  • Thrombocytosis / blood*
  • Ultrasonography