Difference between revisions of "Immune thrombocytopenic purpura"

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==Background==
 
==Background==
===GENERAL===
+
*Acquired autoimmune disease resulting in destruction of platelets
# low platelets and mucocutaneous bleeding
+
*Because circulating plts are functional, significant bleeding usually only once plt <30K
# half occur in kids
+
*Types
# either primary or secondary to other disorder
+
**Acute
# either acute or chronic > 6mo
+
***More common among younger children
# usually presents days to weeks after infection
+
***Affects men/women equally
# in kids, 70% resolve in 6 mo regardless of tx or not
+
***Resolves in 1-2mo
# adults usually chronic, insidous onset and more likely in women than men
+
**Chronic
 +
***Lasts >3mo
 +
***More common in adults and women
 +
***Rarely remits spontaneously or with tx
 +
***More likely to have an ynderlying disease or autoimmune disorder (e.g. SLE)
  
===PATHOPHYS===
+
==Clinical Features==
# mediated by autoantibodies- platelets coated with igg antibodies undergo accelerated clearance in spleen and liver
+
*Petechiae
# can get compensatory increase in platelet production in some pts
+
*Epistaxis, ginigival bleeding, menorrhagia
# 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.
 
 
 
===GENETICS===
 
# 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
 
  
 
==Diagnosis==
 
==Diagnosis==
# is dx of exclusion
+
*Diagnosis of exclusion
#can get secondary ITP in SLE, antiphospholid syn, immune deficiency states, leukemia, lymphoma, HIV, Hep C, heparin and quinidine.
+
**Must differentiate from chronic ITP, which suggests an underlying disorder
# duration of bleeding tells acute from chronic
+
*CBC shows normal cell lines except for the platelets (may have mild anemia)
#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==
 
===ADULTS===
 
# 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.
 
 
 
===KIDS===
 
#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==
 
===ADULTS===
 
#no tx if asymptomatic with plt 30k
 
# splenectomy if relapse or not response to steroids, iv ig or iv anti D ig
 
  
===KIDS===
+
==Treatment==
# delay splenectomy as long as possible- or if symptomatic > 1yr or severe thrombocytopenia
+
===Options===
 +
##Corticosteroids
 +
###First-line in adults
 +
###Prednisone 60-100 mg/d w/ taper after count reaches normal
 +
###Methylprednisolone 30mg/kg/d IV x3d (for life-threatening bleeding)
 +
##IVIG
 +
###First-line in children
 +
###1gm/kg/d x2d
 +
##Anti-D (RhoGAM)
 +
###Pt must be Rh+ for it to work
 +
##Transfusion (platelets)
 +
###Indicated for life-threatening bleeding
 +
###Transfuse only following first dose of methylprednisolone or IVIG
 +
####Holding transfusion until after first dose results in greater rise in plt count
 +
##Estrogen (uterine bleeding)
 +
###25mg IV x1
  
==SPLENECTOMY==
+
===Indications===
# immunize against H flu, pneumoccus, and give daily prophylactic penicilin for 1 yr
+
====Adults====
 +
#Plt >30K and asymptomatic: Usually do not require treatment
 +
#Plt count <30K: Prednisone
 +
#Plt <50K AND bleeding: Prednisone
 +
#Life-threatening bleeding
 +
##IVIG, methylprednisolone, platelet transfusion
  
==Chronic Refractory ITP==
+
====Children====
#30- 40% adults do not respond to splenectomy or have relapse p splenectomy
+
#Plt count >30K: Usually do not require treatment
# hunt for accessory splene
+
#Plt count <20K + significant bleeding: IVIG
# tx with prednisone, iv ig
+
#Plt count <10K: IVIG
# next step is medicine that impedes platelet clearance- Danazol, Dapsone, vinca alkaloids.
+
#Life-threatening bleeding
# if splenectomized, do not give ig anti D ig.
+
##IVIG, methylprednisolone, platelet transfusion
# 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.
 
  
===Children===
+
==Disposition==
# azathioprine alone or in combination with cyclophosphamide.
+
#Admit:
 +
##Pts w/ plt count <20K or those who have significant mucous membrane bleeding
 +
#Discharge:
 +
##Plt counts >20K AND asymptomatic or have only minor petechiae
  
 
==Complications==
 
==Complications==
# fatal bleeding from ICH- risk greatest in elderly or recurrent bleeding or no response to tx
+
#Rare; more common in elderly
 +
##Intracerebral bleeding
 +
##Severe GI bleeding
  
 
==Source ==
 
==Source ==
6/06 MISTRY
+
Tintinalli
  
 
[[Category:Heme/Onc]]
 
[[Category:Heme/Onc]]

Revision as of 09:24, 12 October 2011

Background

  • Acquired autoimmune disease resulting in destruction of platelets
  • Because circulating plts are functional, significant bleeding usually only once plt <30K
  • Types
    • Acute
      • More common among younger children
      • Affects men/women equally
      • Resolves in 1-2mo
    • Chronic
      • Lasts >3mo
      • More common in adults and women
      • Rarely remits spontaneously or with tx
      • More likely to have an ynderlying disease or autoimmune disorder (e.g. SLE)

Clinical Features

  • Petechiae
  • Epistaxis, ginigival bleeding, menorrhagia

Diagnosis

  • Diagnosis of exclusion
    • Must differentiate from chronic ITP, which suggests an underlying disorder
  • CBC shows normal cell lines except for the platelets (may have mild anemia)

Treatment

Options

    1. Corticosteroids
      1. First-line in adults
      2. Prednisone 60-100 mg/d w/ taper after count reaches normal
      3. Methylprednisolone 30mg/kg/d IV x3d (for life-threatening bleeding)
    2. IVIG
      1. First-line in children
      2. 1gm/kg/d x2d
    3. Anti-D (RhoGAM)
      1. Pt must be Rh+ for it to work
    4. Transfusion (platelets)
      1. Indicated for life-threatening bleeding
      2. Transfuse only following first dose of methylprednisolone or IVIG
        1. Holding transfusion until after first dose results in greater rise in plt count
    5. Estrogen (uterine bleeding)
      1. 25mg IV x1

Indications

Adults

  1. Plt >30K and asymptomatic: Usually do not require treatment
  2. Plt count <30K: Prednisone
  3. Plt <50K AND bleeding: Prednisone
  4. Life-threatening bleeding
    1. IVIG, methylprednisolone, platelet transfusion

Children

  1. Plt count >30K: Usually do not require treatment
  2. Plt count <20K + significant bleeding: IVIG
  3. Plt count <10K: IVIG
  4. Life-threatening bleeding
    1. IVIG, methylprednisolone, platelet transfusion

Disposition

  1. Admit:
    1. Pts w/ plt count <20K or those who have significant mucous membrane bleeding
  2. Discharge:
    1. Plt counts >20K AND asymptomatic or have only minor petechiae

Complications

  1. Rare; more common in elderly
    1. Intracerebral bleeding
    2. Severe GI bleeding

Source

Tintinalli