TABLE 93.11 ETIOLOGIES OF REACTIVE THROMBOCYTOSIS Acute infectious disease Chronic infection (tuberculosis, hepatitis, osteomyelitis) Autoimmune/inflammatory disease • Inflammatory bowel disease (IBD) • Kawasaki disease • Ankylosing spondylitis • Rheumatoid arthritis Medication effect • Glucocorticoids • Epinephrine • Low–molecular-weight heparin • Vincristine Malignancy Tissue damage • Postprocedure • Thermal burns • Trauma Asplenia or functional asplenia Iron deficiency Hemolytic anemia Acute blood loss Inflammation Exercise Rebound following thrombocytopenia Management Patients with asymptomatic thrombocytosis not require emergency medical therapy to lower their platelet count; however, they may require treatment directed at the underlying cause of their thrombocytosis Patients should follow up with their primary care provider to ensure platelet count normalization; the platelet count may remain elevated for weeks to months Consultation with a pediatric hematologist is advised if thrombocytosis persists beyond this time frame The use of antiplatelet (e.g., aspirin) or cytoreductive agents (e.g., hydroxyurea, anagrelide) should only be started in consultation with a pediatric hematologist Evidence for their use and the optimal agent