Purpura fulminans (PF) is a haematological emergency in which there is skin necrosis and disseminated intravascular coagulation. This may progress rapidly to multi-organ failure caused by thrombotic occlusion of small and medium-sized blood vessels. PF may complicate severe sepsis or may occur as an autoimmune response to otherwise benign childhood infections. PF may also be the presenting symptom of severe heritable deficiency of the natural anticoagulants protein C or protein S. Early recognition and treatment of PF is essential to reduce mortality and to prevent major long-term health sequelae. However, management strategies require accurate identification of the underlying cause. This review focuses on the clinical features, differential diagnosis and laboratory features of the range of PF disorders and includes expert consensus opinion about immediate and on-going management.