View source for Vaccine-induced immune thrombotic thrombocytopenia

== Background ==

* Very rare

== Clinical Presentation ==

* Follows recent vaccination within 4 to 30 days
* Can present with severe headache, visual changes, abdominal pain, nause and vomiting, back pain, dyspnea, leg pain or swelling, petechiae and easy bruising

== Investigations ==

* CBC with platelet count and peripheral smear
* Imaging tor thrombosis based on the patient's signs and symptoms
* PF4-ELISA [[Heparin-induced thrombocytopenia|HIT]] assay, drawn before starting treatment
* Fibrinogen

== Diagnosis ==

* All four criteria must be met:
** Recent COVID vaccine within 4 to 30 days previously
*** So far only Johnson & Johnson and AstraZeneca
** Thrombosis, often cerebral or abdominal
** Thrombocytopenia, though they may be normal early in the course of illness
** Positive PF4 HIT ELISA

== Management ==

* Should be started if there are signs or symptoms of serious thrombosis and positive imaging or low platelets
* Should be treated with non-heparin anticoagulation

[[Category:Infectious diseases]]
[[Category:Hematology]]