Haemorrhagic smallpox. 2. Specific bleeding and coagulation studies.

A total of 60 patients in Madras with haemorrhagic and non-haemorrhagic clinical forms of smallpox were investigated by a variety of bleeding and coagulation studies in an attempt to reveal specific haematological defects that might account for the haemorrhagic diathesis in certain cases of smallpox.The non-haemorrhagic smallpox patients had no coagulation abnormalities, although some had thrombocytopenia.The early haemorrhagic patients showed a deficiency of platelets, prothrombin and accelerator globulin, and increased circulating antithrombin. Patients with the late form of haemorrhagic smallpox showed significant thrombocytopenia and less severe deficiencies of the same coagulation factors; a few also had increased antithrombin.The authors suggest that therapy with fresh, frozen or lyophilized plasma should be tried; fresh, platelet-rich plasma should offer the greatest benefit.