On the "Easy Bruising" Syndrome with Normal Platelet Count

Abstract

Patients (75) with normal platelet counts were investigated for easy bruising. All had a normal coagulation profile, and all except 4 were women. None were on aspirin or other antiplatelet agents. Two specific groups were delineated. In type 1 (44 patients, mean age, 35), platelet function was normal to supranormal. Megathrombocyte number was elevated in 60% of patients and correlated with the presence of antiplatelet antibody in 30% of patients. In type 2 (31 patients, mean age, 34), platelet function was abnormal: impaired epinephrine aggregation (primary and secondary wave) in 97%, impaired connective tissue aggregation in 77%, and impaired ADP aggregation in 42%. Megathrombocyte number was elevated in 71%, and antiplatelet antibody was present in 38% of patients. The easy brusing syndrome was differentiated into 2 categories: type 1, in which a platelet abnormality is unlikely, and type 2, in which a platelet abnormality exists. Elevated incidence of antiplatelet antibody in both groups suggests a possible autoimmune cause.