Natural history of severe thrombocytopenia in infectious mononucleosis

The natural history of severe thrombocytopenia in two patients with infectious mononucleosis (minimum platelet counts under 10 × 109 and 17 × 109/l respectively) is described. In both, the platelet count rose rapidly and spontaneously, reaching approximately 100 × 109/l on the seventh day. Bleeding symptoms were also transient and never life-threatening. The possibility of very rapid spontaneous recovery from severe thrombocytopenia must be borne in mind in assessing the effect of any drug in the management of this complication of infectious mononucleosis.