A patient with classic symptoms of blood dyscrasia, specifically idiopathic thrombocytopenic purpura, failed to receive laboratory tests because the condition had gone undetected by a dentist and a physician. However, after the patient was given a provisional diagnosis supported by laboratory test results, one of the general treatment procedures for idiopathic thrombocytopenic purpura that consisted of a regimen of corticosteroids was instituted and was proved successful. More radical procedures, such as transfusions of fresh whole blood or of fresh platelets, or a splenectomy, were unnecessary. The responsibility of a dentist to detect oral changes that are not of dental origin is emphasized.