Immune Thrombocytopenia (ITP) in Emergency Medicine Differential Diagnoses

Updated: Sep 13, 2021
  • Author: Michael A Silverman, MD, FACEP; Chief Editor: Gil Z Shlamovitz, MD, FACEP  more...
  • Print

Diagnostic Considerations

Other problems to be considered in the differential diagnosis include the following:

  • Pseudothrombocytopenia (platelet clumping in the presence of ethylenediaminetetraacetic acid [EDTA])
  • Liver disease
  • Myelodysplasia
  • Lymphoproliferative, autoimmune, or infectious diseases
  • Pregnancy-associated thrombocytopenia
  • Drug-induced immune thrombocytopenia (alcohol, heparin, quinine/quinidine, sulfonamides, vaccines [6] )
  • Infection/sepsis (eg, from hepatitis C virus, human immunodeficiency virus, cytomegalovirus, Epstein–Barr virus, severe acute respiratory syndrome coronavirus‐2 [SARS‐CoV‐2] [7] )
  • Acute leukemia
  • Myelodysplastic syndrome
  • Malignancy
  • Megaloblastic anemia
  • Isoimmune neonatal purpura
  • Transfusion
  • Factitious

Immune thrombocytopenia and COVID-19

Mild thrombocytopenia has been reported in approximately 5–10% of patients with symptomatic COVID-19; rarely, severe thrombocytopenia may occur. [7, 8, 9] Case reports of thrombocytopenia following COVID-19 vaccination have also been reported. [10, 11]

In addition, vaccine-induced immune thrombotic thrombocytopenia (VITT)—a novel clinical syndrome with striking similarities to heparin-induced thrombocytopenia but in the absence of heparin exposure—may occur 5-30 days after vaccination with a viral vector–based COVID-19 vaccine. These patients present with mild to severe thrombocytopenia; thrombosis at uncommon sites, including cerebral venous sinus thrombosis and splanchnic venous thrombosis; and positive antibodies against platelet factor 4. [12, 13, 14] VITT is extremely rare. As of May 2021, the estimated incidence was approximately 7-10 cases per million individuals with the AstraZeneca vaccine and approximately 3.2 cases per million with the Johnson & Johnson (Janssen) vaccine. [12]


Differential Diagnoses