Thrombocytosis in Children: A Recent Perspective

Abstract

Thrombocytosis is a common condition in children, including primary and secondary types. Secondary thrombocytosis is often caused by infections, anemia, iron deficiency, trauma, or surgery, generally without serious thrombosis or bleeding. Platelet counts usually return to normal after controlling the primary factors, with a good clinical course and outcomes. Primary thrombocytosis is mainly caused by myeloproliferative neoplasms such as polycythemia vera, primary thrombocythemia, and myelofibrosis, often accompanied by hematopoietic cell gene mutations. Clinical manifestations are atypical compared to adults, with few thromboembolic or bleeding events. Patients who are asymptomatic or have mild symptoms generally do not require special treatment, and it is recommended to monitor platelet values regularly. Antiplatelet therapy with aspirin can be considered for patients at risk of thrombosis or those with extreme thrombocytosis. Cytoreductive therapy can be performed when necessary, but it is important to monitor drug toxicities and side effects closely. Currently, commonly used cytoreductive drugs include hydroxyurea, interferon-alpha, and anagrelide. This article provides an overview of the etiology, clinical manifestations, diagnosis, and treatment of childhood thrombocytosis, aiming to further guide clinicians in treatment decisions.