Coronary arteriography is reserved for patients with persistent echo abnormalities or any patient with myocardial infarction. Sparse perivascular lymphocytic and histiocytic inflammatory infiltrates are seen. There is marked papillary dermal edema, dilatation of blood vessels and exocytosis of lymphocytes. Evidence of vasculitis is most severe in medium-sized arteries. The duration is varied, usually 6-8 weeks.
Prednisone worsens the prognosis.
Long-term therapy to avoid coronary thrombosis includes indefinite use of aspirin if coronary artery abnormalities are detected. The goal of pharmacotherapy is to reduce morbidity and prevent complications. They may decrease autoantibody production, and increase solubilization and removal of immune complexes. 24-48 hours or recurrence of a fever following defervescence after the administration of IVGG should have a repeat dose of gammaglobulin. Myocardial infarction can occur years after the initial illness and these patients should be referred to a cardiologist.