Difference between revisions of "Immune thrombocytopenic purpura"

(Management)
Line 18: Line 18:
 
==Clinical Features==
 
==Clinical Features==
 
*[[Petechiae]]
 
*[[Petechiae]]
*[[Epistaxis]], gingival bleeding, menorrhagia
+
*[[Epistaxis]]
 +
[[Gingival bleeding]]
 +
[[Menorrhagia]]
 +
[[GI bleeding]]
 +
[[Intracranial hemorrhage - rare]]
  
 
==Differential Diagnosis==
 
==Differential Diagnosis==

Revision as of 14:49, 17 November 2016

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

Types

  • Acute
    • More common among younger children
    • Affects men/women equally
    • Resolves in 1-2 months
  • Chronic
    • Lasts > 3 months
    • More common in adults and women
    • Rarely remits spontaneously or with treatment
    • More likely to have an underlying disease or autoimmune disorder (e.g. SLE)

Clinical Features

Gingival bleeding Menorrhagia GI bleeding Intracranial hemorrhage - rare

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[1]
      • 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
    • 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

  • Platlet >30K and asymptomatic: usually do not require treatment
  • Platlet count <30K: prednisone
  • Platlet <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

Disposition

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

Complications

See Also

References