Thrombocytopenia in malaria with immunoglobulin (IgM) changes.

Of 33 cases of naturally occurring human malaria 32 were found to have significant thrombocytopenia. Only one patient showed signs of bleeding. The lowest platelet levels were found between the day of diagnosis and the fourth day of treatment. Thereafter they returned to normal values. No other factors could be found to correlate with the presence or depth of thrombocytopenia, and no evidence of intravascular coagulation was found in any case. A rise in the immunoglobulin IgM was found in all 13 cases in which it was estimated. Since thrombocytopenia can occur independently of intravascular coagulation the latter should be diagnosed and heparin given only after clotting factors have been shown to be depleted.