450 coronary arteries and may lead to aneurysm formation, ischemic heart disease, and/or infarction. 5 Standard treatment for KD includes intra- venous immunoglobulin (IVIG) and oral aspirin (ASA). Patients unre- sponsive to standard therapy may re- quire additional doses of IVIG and/or corticosteroids (adjunctive therapy, ADJ). Kawasaki disease (KD) is a systemic vasculitis that occurs most commonly in children younger than 5 years of age. The inflammation involves small Early treatment with intravenous immunoglobulin in patients with Kawasaki disease Shirley M. L. Tse, MD, FRCPC, Earl D. Silverman, MD, FRCPC, Brian W. McCrindle, MD, FRCPC, and Rae S. M. Yeung, MD, PhD, FRCPC From the Division of Rheumatology and Cardiology, Department of Pediatrics, Hospital for Sick Children, Hospital for Sick Children Research Institute, University of Toronto, Ontario, Canada. Supported by a fellowship provided by the Medical Research Council of Canada and Arthritis Society. Rae S.M. Yeung is a research scholar of The Arthritis Society of Canada. Submitted for publication March 7, 2001; revisions received June 11, 2001, and Sept 26, 2001; accepted Dec 20, 2001. Reprint requests: Rae S. M. Yeung, MD, Division of Rheumatology, Hospital for Sick Children, 555 University Ave, Room 8253, Elm Wing, Toronto, Ontario, Canada M5G 1X8. Copyright © 2002, Mosby, Inc. All rights reserved. 0022-3476/2002/$35.00 + 0 9/21/122469 doi:10.1067/mpd.2002.122469 ADJ Adjunctive therapy ASA Aspirin CAL Coronary artery lesions IVIG Intravenous immunoglobulin KD Kawasaki disease and medium-sized arteries, and the most severe problems arise from coro- nary artery inflammation. Coronary inflammation results in damage to the Objectives: To determine if a shorter interval between Kawasaki disease (KD) treatment with intravenous immunoglob- ulin (IVIG) and fever onset results in increased treatment failures, need for adjunctive therapy, or development of coro- nary artery lesions. Study design: Patients with KD (n = 178; 89 matched pairs) diagnosed between 1987 and 1999 were included in this case-control study. All patients had fever plus at least 4 of the 5 clinical criteria for KD. Eighty-nine patients who re- ceived IVIG at day 5 or earlier were matched to patients diagnosed within 4 weeks and given IVIG at days 6 to 9 of fever. Compiled data from a detailed chart review included demographics, clinical features, fever duration, investigations, dis- ease course, and response to therapy. Differences between matched case and control pairs were analyzed by means of t tests and McNemar tests. Results: No demographic differences were noted between the two groups. Patients treated on day 5 or less of fever had a shorter total fever duration (5.2 ± 1.9 days vs 8.0 ± 1.8 days, P < .0001), longer fever after IVIG treatment (1.5 ± 1.9 days vs 0.8 ± 1.3 days, P = .008), and less coronary artery ectasia at 1 year after KD onset (4% vs 16%, P = .02). There was no significant difference between cases and control patients in the number of patients with KD recrudes- cence, need for repeat courses of IVIG, need for corticosteroids, length of hospitalization, or development of coro- nary artery aneurysms within the first 3 months. Patients who were treated on day 5 or less of fever had higher levels of serum albumin (36 ± 5 g/L vs 33 ± 5 g/L, P < .01) and serum ALT (115 ± 155 U/L vs 46 ± 49 U/L, P < .001) as well as a lower platelet count (354 ± 131 vs 403 ± 166, P = .02) than did control patients during the acute phase. Conclusions: Early treatment of KD resulted in less coronary ectasia at 1 year after KD onset but was not associated with a quicker resolution of fever, an increased number of treatment failures, an increased need for adjunctive therapy, length of hospitalization, nor development of coronary artery lesions. In children with fever and classic clinical and labo- ratory findings of KD, treatment with IVIG on or before 5 days of fever resulted in better coronary outcomes and de- creased the total length of time of clinical symptoms. (J Pediatr 2002;140:450-5)