Introduction Compared with adults, children are relatively protected from venous and arterial thrombosis. Advances in the treatment and supportive care of critically ill children, along with heightened awareness of thrombotic complications, have resulted in an increase in the diagnosis of…
Introduction Venous thromboembolism (VTE) poses a number of challenges and opportunities to the practicing hematologist. The duration of anticoagulation is a frequent reason for consultation because it poses difficult questions of risk and benefit. Although the practical frustrations of anticoagulation…
Introduction Viral, bacterial, fungal, and parasitic infections may all cause disturbances in hemostasis, which can eventually lead to thrombohemorrhagic complications such as disseminated intravascular coagulation (DIC), hemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP), or even vasculitis. Symptoms and signs…
An enormous amount has been written about disseminated intravascular coagulation (DIC). During the 1970s and 1980s, it was rather fashionable to report yet another new and unique “cause” of DIC. However, over the past few decades, it has become increasingly…
Hereditary hemorrhagic telangiectasia (HHT) also known as Osler-Weber-Rendu (OWR) disease is an inherited disorder that leads to the development of mucocutaneous telangiectasia and visceral organ arteriovenous malformations (AVMs). HHT is the result of mutations in key regulators of angiogenesis, which…
Confined to the vascular system, blood comes into contact only with endothelial cells, which line all macrovascular, microvascular, and sinusoidal systems. Disruption of this closed system leads to bleeding—either gross bleeding (characteristic of macrovascular hemorrhage) or extravasation into tissue or…
Introduction Platelet dysfunction and thrombocytopenia result from a variety of inherited and acquired disorders. When a patient with mucocutaneous bleeding is first evaluated, the list of differential diagnoses is usually extensive. Elements of the medical history, the physical examination, and…
Immune thrombocytopenia (ITP), formerly called idiopathic thrombocytopenic purpura, is a common acquired bleeding disordered characterized by isolated thrombocytopenia in the absence of a clinically apparent cause. Currently there is no diagnostic test for ITP; thus establishing the diagnosis can be…
Introduction Of the circulating blood cells, the platelet was the last to be fully described and its attributes determined. Although early studies by Osler, Hayam, and Bizzozero had identified small particles in the blood, these were thought to be bacteria,…
von Willebrand disease (VWD), transmitted in an autosomal fashion, is the most common of the inherited bleeding disorders. It is caused by a decrease in the quantity of von Willebrand factor (VWF) or a qualitatively abnormal VWF in the circulation…