0521779407-10 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 18:40
808 Idiopathic (Immune) Thrombocytopenic Purpura (ITP)Idiopathic (Immune) Thrombocytopenic Purpura (ITP)........
MORTIMER PONCZ, MD and MICHELE LAMBERT, MDhistory & physical
■Peak age: 2–4 years old; >10 years old more likely to have chronic ITP.
■Males and females equally affected in childhood ITP; females pre-
dominate 3:1 in adult ITP.
■Sudden onset of bruising, petechiae, epistaxis, oral mucosal bleed-
ing
■More rarely, menorrhagia, hematuria, GI bleed, intracranial hemor-
rhage in an otherwise healthy child
■Often preceding viral illness (could be diarrheal) or immunization
1–3 weeks prior to presentation
■Can complicate HIV infection
■Medication history: aspirin, sulfonamides, heparin, quinidine, anti-
convulsants
■Hemolytic anemia: jaundice, dark brown urine, pallor (if blood lost
or Evan’s syndrome and not ITP)tests
■CBC, reticulocyte count, PT, PTT
■Review peripheral smear for platelet size and number, WBC mor-
phology, RBC fragments, spherocytes.
■Coombs/direct antiglobulin test: rule out hemolytic anemia compo-
nent associated with Evan’s syndrome
■ANA in the older child, especially girls; can be presentation for SLE
■Blood type if intravenous anti-Rh(D) immunoglobulin treatment
considered
■Bone marrow aspiration: not required for diagnosis but may be
done prior to steroid use. Many now feel if there is good initial
response to immune modulation (IVIG or anti-Rh(D), this is suffi-
cient for diagnosis; normal or increased numbers of megakaryocytes
in ITP; increased erythropoiesis if hemolytic component present; no
leukemia or tumor clumps.
■Low thrombopoietin levels (not measured in straightforward
cases)
■Elevated platelet-associated IgG (not measured in straightforward
cases)
■Iron deficiency possible if prolonged bleeding