Steven Wasnt In Morning Report....

Young person presents with platelets of 4......

Differential Diagnosis of Thrombocytopenia

Decreased Platelet Production
•Marrow: fibrosis, aplasia/dysplasia (Fanconi’s), infiltration
•Cytotoxic agents / radiation
•Viral: HIV, EBV, parvo, mumps
•Other infection: infectious infiltration of marrow
•ETOH
•Vitamin deficiency: B12, folate

Accelerated Destruction:
•microangiopathic disease: TTP/HUS, DIC, HELLP, PET, malignant hypertension
•Vasculitis
•Prosthetic heart valves
•Other mechanical: IABP, hemangiomas
•Infection: malaria
•Immune:
•autoimmune – ITP
•allo immune – post transfusion purpura
•secondary: SLE, APLA, CLL drugs (heparin, quinidine, etc), HIV

Distribution / Dilutional
•Splenic sequestration
•Pregnancy

Pseudothrombocytopenia

Idiopathic Immune Thrombocytopenia Purpura

The diagonsis of ITP is a diagnosis of exclusion after consideration / work up of other enities listed in the differential. A bone marrow biopsy may or may not be part of your work up but is not considered necessary in all patients. Criteria which should prompt bone marrow biopsy include:
•Age >60
•Other cytopenias
•Poor response to treatment
•Significant splenomegaly

First line treatment of acute ITP is steroids. Please see NEJM review for more details. http://content.nejm.org/cgi/reprint/346/13/995.pdf

More recently another treatment strategy has been proposed with high dose, short course steroids (dexamethasone). Check out this article in Blood which is the most recent of 2 trials that test this strategy: Blood. 2007 Feb 15;109(4):1401-7. Epub 2006 Oct 31.