Acquired platelet dysfunction with eosinophilia in children in the south of Thailand.

One hundred and sixty-eight children aged 13 months to 12.6 years with acquired platelet dysfunction with eosinophilia (APDE) were studied. The male to female ratio was 1.15:1. All of the children were in good health and no history of any drug ingestion was detected. All of the children had widespread spontaneous bruising on the extremities, body and face off and on. Severe bleeding symptoms were detected in 8% of these patients. The number of platelets in these children was within the normal range but the platelet morphology was abnormal in all of them. Eosinophilia was detected in 86% of these children. Prolonged bleeding time was detected in 53% of these patients. Abnormal platelet adhesiveness was found in 33% of cases. Abnormal platelet aggregation induced by collagen was the most sensitive test in these patients. Abnormal ADP release from the platelets was detected in these patients by the absence of a second wave of aggregation during stimulation of PRP by ADP or epinephrine. Abnormal or no ATP secretion from the platelets during stimulation by ADP, epinephrine or collagen was detected in these patients. Ristocetin-induced platelet aggregation was normal in these children. Decreased or absence of platelet dense granules by TEM study was detected in some patients. These changes in platelet functions and morphology may be due to acquired storage pool deficiency of the platelet. Parasitic infection was detected in 56% of these children. About 83% of these children with APDE had serum total IgE higher than 100 IU/ml. There was no correlation between the number of eosinophils and serum total IgE and the severity of bleeding symptoms. The majority of children with APDE did not receive any treatment except those who had severe bleeding symptoms which required platelet concentrate to stop bleeding. In more than 90% of the patients, the bruising or ecchymosis disappeared within 6 months and the abnormal platelet functions returned to normal within 4 months. Recurrence of these bleeding syndromes was detected in 7% of the children.