Difference between revisions of "Immune thrombocytopenic purpura"

(Other Options)
(44 intermediate revisions by 12 users not shown)
Line 1: Line 1:
 
==Background==
 
==Background==
 +
*Abbreviation: ITP
 +
*Known as both "idiopathic" or "immune" thrombocytopenic purpura
 
*Acquired autoimmune disease resulting in destruction of platelets
 
*Acquired autoimmune disease resulting in destruction of platelets
*Because circulating plts are functional, significant bleeding usually only once plt <30K
+
*Because circulating platelets are functional, life-threatening bleeding only once platelet count <10K
*Types
+
*Chronically, the disease follows a course that is usually stable with intermittent and episodic flares, leading to clinically relevant thrombocytopenia<ref>Cines DB and Blanchette VS.  Immune Thrombocytopenic Purpura. New England Journal of Medicine.  Vol 346 (13); 995-1008.</ref>
**Acute
+
 
***More common among younger children
+
===Types===
***Affects men/women equally
+
{| {{table}}
***Resolves in 1-2mo
+
| align="center" style="background:#f0f0f0;"|'''Charateristic'''
**Chronic
+
| align="center" style="background:#f0f0f0;"|'''Acute ITP'''
***Lasts >3mo
+
| align="center" style="background:#f0f0f0;"|'''Chronic ITP'''
***More common in adults and women
+
|-
***Rarely remits spontaneously or with tx
+
| Common age group||Younger children||Adults
***More likely to have an ynderlying disease or autoimmune disorder (e.g. SLE)
+
|-
 +
| Sex||Affects men/women equally||Usually women
 +
|-
 +
| Duration||Resolves in 1-2 months||Lasts > 3 months
 +
|-
 +
|Cause||Typically follows viral illness||More likely to have an underlying disease or autoimmune disorder (e.g. SLE)
 +
|-
 +
| Prognosis||||Rarely remits spontaneously or with treatment
 +
|}
  
 
==Clinical Features==
 
==Clinical Features==
*Petechiae
+
*[[Petechiae]]
*Epistaxis, ginigival bleeding, menorrhagia
+
*[[Epistaxis]]
 +
*[[Gingival bleeding]]
 +
*[[Vaginal Bleeding (Non-Pregnant)|Menorrhagia]]
 +
*[[GI bleeding]]
 +
*[[Intracranial hemorrhage]]
 +
 
 +
==Differential Diagnosis==
 +
{{Thrombocytopenia}}
 +
 
 +
{{Purpura DDX}}
  
==Diagnosis==
+
==Evaluation==
 
*Diagnosis of exclusion
 
*Diagnosis of exclusion
**Must differentiate from chronic ITP, which suggests an underlying disorder
+
*Must differentiate acute ITP from chronic ITP, which suggests an underlying disorder
 
*CBC shows normal cell lines except for the platelets (may have mild anemia)
 
*CBC shows normal cell lines except for the platelets (may have mild anemia)
  
==Treatment==
+
==Management==
 
===Options===
 
===Options===
##Corticosteroids
+
*'''First choice in adults:''' Corticosteroids
###First-line in adults
+
**[[Prednisone]] 60-100mg/d with taper after count reaches normal (50-75% remission rate by 3 wks)
###Prednisone 60-100 mg/d w/ taper after count reaches normal
+
**[[Methylprednisolone]] 30mg/kg/d IV x 3 days (for life-threatening bleeding)
###Methylprednisolone 30mg/kg/d IV x3d (for life-threatening bleeding)
+
*'''First choice in children:''' Intravenous Immunoglobulin G ([[IVIG]]) 1gm/kg/d x 2 days
##IVIG
+
*High dose Anti-D ([[RhoGAM]]): patient must be Rh+ for it to work
###First-line in children
+
**Causes shift towards splenic destruction of antibody-coated Rh+ RBCs
###1gm/kg/d x2d
+
**Thereby has less functional capacity to destroy platelets
##Anti-D (RhoGAM)
+
**Dosage dependent on Hb level in mg/dL<ref>eMedicine. RhoGAM. http://reference.medscape.com/drug/rhogam-hyperrho-s-d-rho-d-immune-globulin-343143.</ref>
###Pt must be Rh+ for it to work
+
***Hb>10, 250 IU/kg IV x1 over 5min
##Transfusion (platelets)
+
***Hb<10, 125 IU/kg IV x1 over 5min
###Indicated for life-threatening bleeding
+
*[[Platelet transfusion]]
###Transfuse only following first dose of methylprednisolone or IVIG
+
**Indicated for life-threatening bleeding  
####Holding transfusion until after first dose results in greater rise in plt count
+
**Will ultimately be destroyed
##Estrogen (uterine bleeding)
+
**Transfuse only following first dose of [[methylprednisolone]] or [[IVIG ]]
###25mg IV x1
+
***Holding transfusion until after first dose results in greater rise in platelet count
 +
***Calculate number of packs needed to increase count to over 50k (1 pack generally increases by 10k)
 +
*Estrogen for uterine bleeding: 25mg IV x1
  
 
===Indications===
 
===Indications===
 
====Adults====
 
====Adults====
#Plt >30K and asymptomatic: Usually do not require treatment
+
*Platelet >30K and asymptomatic: usually do not require treatment
#Plt count <30K: Prednisone
+
*Platelet count <30K: [[prednisone]]
#Plt <50K AND bleeding: Prednisone
+
*Platelet <50K AND bleeding: [[prednisone]]
#Life-threatening bleeding
+
*Life-threatening bleeding: IVIG, methylprednisolone, platelet transfusion
##IVIG, methylprednisolone, platelet transfusion
 
  
 
====Children====
 
====Children====
#Plt count >30K: Usually do not require treatment
+
*Platelet count >30K: usually do not require treatment
#Plt count <20K + significant bleeding: IVIG
+
*Platelet count <20K + significant bleeding: IVIG
#Plt count <10K: IVIG
+
*Platelet count <10K: IVIG
#Life-threatening bleeding
+
*Life-threatening bleeding: IVIG, methylprednisolone, platelet transfusion
##IVIG, methylprednisolone, platelet transfusion
+
 
 +
===Other Options===
 +
*[[Splenectomy]] if above fails (only 2/3 effective)
 +
*[[Rho(D) Immune Globulin (RhoGAM)]]
 +
**Will induce mild hemolysis in Rh+ patients that decreases macrophage activity
 +
**Spleen will not destroy platelets covered in antibodies
 +
*[[Rituximab]]
 +
**May help as ITP is autoimmune process
  
 
==Disposition==
 
==Disposition==
#Admit:
+
*'''Admit:''' platelet count <20K or significant mucous membrane bleeding
##Pts w/ plt count <20K or those who have significant mucous membrane bleeding
+
*'''Discharge:''' platelet count >20K AND asymptomatic '''OR''' only minor petechiae
#Discharge:
 
##Plt counts >20K AND asymptomatic or have only minor petechiae
 
  
 
==Complications==
 
==Complications==
#Rare; more common in elderly
+
*Rare: more common in elderly
##Intracerebral bleeding
+
**[[Intracerebral bleeding]]
##Severe GI bleeding
+
**Severe [[GI bleeding]]
  
==Source ==
+
==See Also==
Tintinalli
+
*[[ITP in Pregnancy]]
  
 +
==References==
 +
<references/>
 
[[Category:Heme/Onc]]
 
[[Category:Heme/Onc]]

Revision as of 14:49, 1 September 2019

Background

  • Abbreviation: ITP
  • Known as both "idiopathic" or "immune" thrombocytopenic purpura
  • Acquired autoimmune disease resulting in destruction of platelets
  • Because circulating platelets are functional, life-threatening bleeding only once platelet count <10K
  • Chronically, the disease follows a course that is usually stable with intermittent and episodic flares, leading to clinically relevant thrombocytopenia[1]

Types

Charateristic Acute ITP Chronic ITP
Common age group Younger children Adults
Sex Affects men/women equally Usually women
Duration Resolves in 1-2 months Lasts > 3 months
Cause Typically follows viral illness More likely to have an underlying disease or autoimmune disorder (e.g. SLE)
Prognosis Rarely remits spontaneously or with treatment

Clinical Features

Differential Diagnosis

Thrombocytopenia

Decreased production

Increased platelet destruction or use

Drug Induced

Comparison by Etiology

ITP TTP HUS HIT DIC
↓ PLT Yes Yes Yes Yes Yes
↑PT/INR No No No +/- Yes
MAHA No Yes Yes No Yes
↓ Fibrinogen No No No No Yes
Ok to give PLT Yes No No No Yes

Petechiae/Purpura (by cause)

Evaluation

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

Management

Options

  • First choice in adults: Corticosteroids
    • Prednisone 60-100mg/d with taper after count reaches normal (50-75% remission rate by 3 wks)
    • Methylprednisolone 30mg/kg/d IV x 3 days (for life-threatening bleeding)
  • First choice in children: Intravenous Immunoglobulin G (IVIG) 1gm/kg/d x 2 days
  • High dose Anti-D (RhoGAM): patient must be Rh+ for it to work
    • Causes shift towards splenic destruction of antibody-coated Rh+ RBCs
    • Thereby has less functional capacity to destroy platelets
    • Dosage dependent on Hb level in mg/dL[2]
      • Hb>10, 250 IU/kg IV x1 over 5min
      • Hb<10, 125 IU/kg IV x1 over 5min
  • Platelet transfusion
    • Indicated for life-threatening bleeding
    • Will ultimately be destroyed
    • Transfuse only following first dose of methylprednisolone or IVIG
      • Holding transfusion until after first dose results in greater rise in platelet count
      • Calculate number of packs needed to increase count to over 50k (1 pack generally increases by 10k)
  • Estrogen for uterine bleeding: 25mg IV x1

Indications

Adults

  • Platelet >30K and asymptomatic: usually do not require treatment
  • Platelet count <30K: prednisone
  • Platelet <50K AND bleeding: prednisone
  • Life-threatening bleeding: IVIG, methylprednisolone, platelet transfusion

Children

  • Platelet count >30K: usually do not require treatment
  • Platelet count <20K + significant bleeding: IVIG
  • Platelet count <10K: IVIG
  • Life-threatening bleeding: IVIG, methylprednisolone, platelet transfusion

Other Options

  • Splenectomy if above fails (only 2/3 effective)
  • Rho(D) Immune Globulin (RhoGAM)
    • Will induce mild hemolysis in Rh+ patients that decreases macrophage activity
    • Spleen will not destroy platelets covered in antibodies
  • Rituximab
    • May help as ITP is autoimmune process

Disposition

  • Admit: platelet count <20K or significant mucous membrane bleeding
  • Discharge: platelet count >20K AND asymptomatic OR only minor petechiae

Complications

See Also

References

  1. Cines DB and Blanchette VS. Immune Thrombocytopenic Purpura. New England Journal of Medicine. Vol 346 (13); 995-1008.
  2. eMedicine. RhoGAM. http://reference.medscape.com/drug/rhogam-hyperrho-s-d-rho-d-immune-globulin-343143.