Immunologic Idiopathic Thrombocytopenic Purpura

A mother, fearing that her 4-year-old son had been abused at his day-care center, rushed him to the emergency department, where an evaluation revealed a platelet count of 1,000/µL. Except for bruises on the boy's face and legs, the physical findings were normal. Bone marrow aspiration showed numerous megakaryocytes and was otherwise normal. The youngster's history included treatment for bronchitis, sinusitis, and conjunctivitis 2 weeks earlier.

This child has immunologic idiopathic thrombocytopenic purpura (ITP), here manifested by generalized petechiae and multiple ecchymoses of the lower extremities and forehead. Acute ITP generally is a self-limited disorder of short duration that develops after a viral infection. The adult, chronic form of this condition manifests with the same skin signs, but it erupts spontaneously and apparently is not preceded by another disease. Platelet antibodies are evident in both forms of the illness.

This child was treated with injury precautions and intravenous g-globulin. After 48 hours, his platelet count rose to 56,000/µL; 9 days later, the platelet count was 304,000/µL. He recovered uneventfully, and there was no further bleeding.

In the adult ITP patient, oral corticosteroids may be given to increase platelet count. Platelet transfusions can be considered if bleeding is life-threatening. Splenectomy is an option in emergency situations or when the condition is refractory to other therapies.