1. November 23, 2010

4. Idiopathic Throbocytopenic Purpura

5. Idiopathic Thrombocytopenic Purpura • Most common cause of isolated thrombocytopenia in otherwise healthy children • Antiplatelet antibody • Binds to platelet surface • Destruction by phagocytosis(spleen, liver) • 50% follow viral illness • Following live vaccines (MMR)

6. Clinical Presentation • History/Physical • Sudden onset petechiae/bruising • Mucosal hemorrhage 30% • Severe bleeding in only 3% • Labs • Isolated thrombocytopenia • <20K (frequently <5K) • Normal Hgb, MCV, WBC, PT/PTT • Smear unremarkable • paucity of platelets (large platelets)

7. Acute ITP • Resolves spontaneously within 6 months • Bleeding tendency lessens within 1-2wks

8. Treatment • Avoidance of NSAIDS • Limit activities • No contact sports • Reassurance of parents

9. Reassurance • Life-threatening hemorrhage very rare • Intracranial hemorrhage 0.5 to 0.1% • Young platelets • Large • Metabolically active • “Sticky” • Underestimated by cell counter

10. Treatment • Prednisone • IVIG • Rho(D) Immune Globulin • Avoid platelet transfusion • Rapidly destroyed • Consider with life-threatening bleed

11. Treatment: Steroids • Prednisone • 1-2 mg/kg/day • Decreases as prednisone tapered (2-3wks)

12. Treatment: IVIG • Costly • More effective than steroids • 80-90% plts >20k within 3 days • Not shown to prevent serious bleeding • Side effects

13. Treatment: Rho(D) Immune globulin • May be used if: • Hgb >10 • Rh + • Efficacy similar to that of IVIG • Hemolysis possible

14. Chronic ITP

15. Chronic ITP • >6 months duration • Generally benign • Not requiring aggressive therapy • Platelets 30-80k • Some bruising and petechiae

16. Chronic ITP • Treatment with steroids, IVIG, Rho(D)IG • Transient increased platelets • Not curative • Useful in emergency or at surgery

17. Chronic ITP • Most improve over time • Allow school and childhood activities • NO contact sports • Splenectomy in refractory cases • 60-80% cure rate

18. Congenital Disorders

19. Wiskott-Aldrich Syndrome • X-Linked • Recurrent infections • Otitis, Pneumonia • Thrombocytopenia • LOW MPV (mean plt volume) • Risk for malignancies • Treatment: B.M. Transplant

20. Thrombocytopenia Absent Radius • WBC usually high • Normal Hgb • Symptomatic by 4 m/o

21. Think about it… • Child with bleeding • Normal: • Plt count • Coags • GlanzmannThrombasthenia • Disorder of platelet Function • NSAIDS overdose • Abnormal function