Reaction at the bacillus Calmette--Guérin inoculation site in patients with Kawasaki disease.

BACKGROUND: The bacillus Calmette-Guérin (BCG) reaction is not included in the classical clinical criteria for Kawasaki disease (KD). However, a reaction at the BCG inoculation site has been mentioned among the "other clinical findings" that are present in about 30-50% of KD patients. The objective of this study was to investigate the clinical characteristics of KD patients with reactions at the BCG inoculation site.

METHODS: A retrospective study of all patients diagnosed with KD between September 2000 and August 2010 was performed. The clinical presentations, laboratory results, treatment outcomes, and coronary artery abnormalities in the BCG-reactive [BCG(+)] and BCG-nonreactive [BCG(-)] groups were analyzed and compared.

RESULTS: In total, 145 patients with KD diagnosed at our institution were included; 46 (31.7%) had a reaction at the BCG inoculation site. The BCG(+) group was younger than the BCG(-) group. Laboratory results showed higher white blood cell counts, platelet counts, and serum potassium levels, and lower low-density lipoprotein levels in the BCG(+) group. The BCG(+) group had a shorter fever duration before intravenous immunoglobulin treatment and a shorter total fever duration than the BCG(-) group. Multivariable logistic regression analysis showed that the age at diagnosis was the only factor significantly associated with a reaction at the BCG inoculation site in KD patients.

CONCLUSIONS: In countries with a national BCG vaccination program, a reaction at the BCG inoculation site could be a useful and early diagnostic sign of KD among younger patients, especially those younger than 6 months.