Introduction
An outbreak of novel coronavirus (2019-nCoV) that began in Wuhan, China, is now a major public health concern worldwide. After the first reported case in the state of Washington, the number of cases in the United States has rapidly increased to over 2 000 000 with more than 100 000 deaths.1 In addition to the typical presentation of respiratory symptoms, hematologic complications have been a significant concern in these patients.
Thrombocytopenia has been reported in up to 55% of patients with COVID-19.2 A meta-analysis of 9 studies has shown that platelet counts were significantly lower in those with more severe COVID-19 infection, and thrombocytopenia predicts mortality.2 Heparin-induced thrombocytopenia (HIT) is a differential for thrombocytopenia, especially in the intensive care setting. In one review, the authors suggested that clinicians routinely evaluate all COVID-19 patients on heparin for indices of HIT by performing the 4T score.3 We report a case of HIT in a patient with critical COVID-19 infection. Also, we briefly describe 4 other cases that were initially managed as HIT, until proven later not to be true HIT, based on the functional assay.