Immune thrombocytopenic purpura

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- low platelets and mucocutaneous bleeding

- half occur in kids

- either primary or secondary to other disorder

- either acute or chronic > 6mo

- usually presents days to weeks after infection

- in kids, 70% resolve in 6 mo regardless of tx or not

- adults usually chronic, insidous onset and more likely in women than men


- mediated by autoantibodies- platelets coated with igg antibodies undergo accelerated clearance in spleen and liver

- can get compensatory increase in platelet production in some pts

- in other pts, get abnormal production destruction of intermedullary antibody coated platelets

- level of thrombopoietin not increased

- methods to tx are directed at 1- antibody prodctn, 2- platelet sensitization, 3- clearance, 4- production.


- can be seen in certain families and twins

- HLA type may predict response to different tx's

- no consistent assoc btwn HLA types and ITP however


- is dx of exclusion

-can get secondary ITP in SLE, antiphospholid syn, immune deficiency states, leukemia, lymphoma, HIV, Hep C, heparin and quinidine.

- duration of bleeding tells acute from chronic

-absence of systemic symptoms helps rule out secondary forms and other dxs

- family hx usually negative.

- physical exam shows platelet type bleeding-petechia, purpura, conj hem,

- if spleen very big, consider other dx

- can see anemia if have lots of blood loss

- can see large young plateltets on perif smear

- bone marrow bx- debatetable- but need it if atypical case, fever, pain, neutropenia, unexplained macrocytosis.

- dx by measuring platelet assoc antibodies- fair sensitivity, specificity and predictive value

- neg test does not rule it out

Initial Management


- if plts above 50k- will dx incidentally

- plts 30k- 50k- will get easy bruising

- petechia and purpura at 1-k- 30k

<10k at risk for internal bleeding

- adults usually require tx with prednsone at tme of presentation

- can also use Anti- D immune globulin in Rh + pt

- IV IG used for internal bleeding

- splenectomy within 3- 6mo if more than 10- 20 mg prednisone per day.


-outcome so good usually dont need to tx unless risk of intracranial hem- plts <10k- 20k

- usually observe and avoid sports, ASA..

- if severe thrombocytopenia- can tx with IV IG or anti D IG. or prednisone.

Urgent Tx in Kids

- neuro sxs, internal bleeding, surgery- tx with iv solumedrol and iv ig and platelet infusion

- consider vincristine

- consider splenectomy

- plasmapharesis not helpful

- consider antifibrinolytic/ aminocaproic acid fo mucosal bleeding

- for severe bleeding- iv ig and iv platelets

Management of First Relapse


-no tx if asymptomatic with plt 30k

- splenectomy if relapse or not response to steroids, iv ig or iv anti D ig


- delay splenectomy as long as possible- or if symptomatic > 1yr or severe thrombocytopenia


- immunize against H flu, pneumoccus, and give daily prophylactic penicilin for 1 yr

Chronic Refractory ITP

-30- 40% adults do not respond to splenectomy or have relapse p splenectomy

- hunt for accessory splene

- tx with prednisone, iv ig

- next step is medicine that impedes platelet clearance- Danazol, Dapsone, vinca alkaloids.

- if splenectomized, do not give ig anti D ig.

- immunesuppression if platelet <20k and no response to above tx- use azathioprine or cyclophosphamide

- Azathioprine watch LFT's- is also carcinogenic

- Cyclophoshamide- marrow suppression, hem cystitis, bladder fibrosis, alopecia, infertility, leukemia and teratogenic.


- azathioprine alone or in combination with cyclophosphamide.


- fatal bleeding from ICH- risk greatest in elderly or recurrent bleeding or no response to tx