Immune thrombocytopenic purpura

This page is for adult patients. For pediatric patients, see: Immune thrombocytopenic purpura (peds) or ITP in Pregnancy for pregnancy related.

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]

Acute vs Chronic ITP

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

Petechiae in a patient with ITP.
Petechiae on the tongue in a patient with ITP.
Petechiae on the lower leg in a patient with ITP.
Unprovoked gingival bleeding as a presenting symptom in ITP.

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

Adults

  • Patients with severe bleeding should receive high dose steroids (ie methylprednisolone 1g IV vs dexamethasone 40mg IV), IVIG (1g/kg), and platelet transfusion[2]
  • Adults with minor mucosal or no bleeding and a platelet count <30x109/L should receive steroids[3]
    • Suggested regimens: prednisone 0.5-2mg/kg/day for 14 days with taper vs dexamethasone 40mg/day for 4 days

Pediatrics

  • Patients with severe bleeding should receive high dose steroids (ie methylprednisolone 30mg/kg IV vs dexamethasone 28mg/m2 IV), IVIG (1g/kg), and platelet transfusion[4]
  • Patients with a non-life-threatening bleed or reduced quality of life can receive prednisone 2-4mg/kg/day for up to 7 days[5]
  • Patients with mild or no bleeding have no benefit with steroids or IVIG regardless of platelet count[6]

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
  • Thrombopoietin receptor agonists (eltrombopag, romiplsotim) may be effective in steroid-refractory cases

Disposition

Adults

  • Admit any patient with significant bleeding or platelet count < 20 x109
  • Patients without significant bleeding and a platelet count > 20 x109 can be managed as an outpatient with hematology

Pediatrics

  • Admit patients with significant bleeding
  • Patients with minor or no bleeding may be saely managed as an outpatient with hematology regardless of patient count.

Complications

See Also

References

  1. Cines DB and Blanchette VS. Immune Thrombocytopenic Purpura. New England Journal of Medicine. Vol 346 (13); 995-1008.
  2. Neunert C, Terrell DR, Arnold DM, Buchanan G, Cines DB, Cooper N, Cuker A, Despotovic JM, George JN, Grace RF, Kühne T, Kuter DJ, Lim W, McCrae KR, Pruitt B, Shimanek H, Vesely SK. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019 Dec 10;3(23):3829-3866. doi: 10.1182/bloodadvances.2019000966. Erratum in: Blood Adv. 2020 Jan 28;4(2):252. PMID: 31794604; PMCID: PMC6963252.
  3. Neunert C, Terrell DR, Arnold DM, Buchanan G, Cines DB, Cooper N, Cuker A, Despotovic JM, George JN, Grace RF, Kühne T, Kuter DJ, Lim W, McCrae KR, Pruitt B, Shimanek H, Vesely SK. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019 Dec 10;3(23):3829-3866. doi: 10.1182/bloodadvances.2019000966. Erratum in: Blood Adv. 2020 Jan 28;4(2):252. PMID: 31794604; PMCID: PMC6963252.
  4. Neunert C, Terrell DR, Arnold DM, Buchanan G, Cines DB, Cooper N, Cuker A, Despotovic JM, George JN, Grace RF, Kühne T, Kuter DJ, Lim W, McCrae KR, Pruitt B, Shimanek H, Vesely SK. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019 Dec 10;3(23):3829-3866. doi: 10.1182/bloodadvances.2019000966. Erratum in: Blood Adv. 2020 Jan 28;4(2):252. PMID: 31794604; PMCID: PMC6963252.
  5. Neunert C, Terrell DR, Arnold DM, Buchanan G, Cines DB, Cooper N, Cuker A, Despotovic JM, George JN, Grace RF, Kühne T, Kuter DJ, Lim W, McCrae KR, Pruitt B, Shimanek H, Vesely SK. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019 Dec 10;3(23):3829-3866. doi: 10.1182/bloodadvances.2019000966. Erratum in: Blood Adv. 2020 Jan 28;4(2):252. PMID: 31794604; PMCID: PMC6963252.
  6. Neunert C, Terrell DR, Arnold DM, Buchanan G, Cines DB, Cooper N, Cuker A, Despotovic JM, George JN, Grace RF, Kühne T, Kuter DJ, Lim W, McCrae KR, Pruitt B, Shimanek H, Vesely SK. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019 Dec 10;3(23):3829-3866. doi: 10.1182/bloodadvances.2019000966. Erratum in: Blood Adv. 2020 Jan 28;4(2):252. PMID: 31794604; PMCID: PMC6963252.