Thrombocytopenia is a risk factor for increased mortality and morbidity during the Coronavirus Disease 2019 (COVID-19). In patients with COVID-19, the mechanisms lead to thrombocytopenia seems to be multifactorial. Thrombotic consumption of platelets in microvasculature, cytokine release, sepsis, and drug induced, direct infection of megakaryocytes and autoimmune destruction of platelets are the leading etiologies in COVID-19 and thrombocytopenia. In this overview, the research was conducted by screening the relevant articles evaluating the COVID-19 associated thrombocytopenia in children. An electronic search was performed in online databases of Scopus, EMBASE, Cochrane, Web of Science and Medline (via PubMed) with English language from December 2019 up to September 2020.
Thrombocytopenia at admission in patients with SARS-CoV-2 infection is common, but delayed phase thrombocytopenia (occurring 2 weeks after beginning of symptoms) is uncertain. The delayed phase thrombocytopenia in COVID-19 is more prevalent in infected case with low lymphocyte count at admission and has a significant correlation with higher mortality rate. In majority of cases with COVID-19 and thrombocytopenia, the platelet count is mildly decreased. Severe thrombocytopenia or a prompt decline in number of platelets often indicates immune mediated thrombocytopenia or in late terminal stages of this infection. Thrombocytopenia is a significant finding in patients with severe type of COVID -19. Immune mediated platelet destruction might account for the delayed-phase thrombocytopenia in a group of patients, and can manifest as severe thrombocytopenia. It is important for practitioners to be vigilant and aware of this hematologic abnormality.