Kawasaki disease is an inflammation of the blood vessels (vasculitis) which predominantly affects young children, under the age of five years. It was first recognised in children in Japan and is the most common cause of acquired heart disease in children in developed countries. Kawasaki disease can be difficult to diagnose because it has similar symptoms to many common childhood infections. The most important complication of Kawasaki disease is caused by inflammation of the heart (coronary) arteries supplying blood to the heart muscle. This may lead to immediate heart problems and damage to the coronary arteries can also have long-term effects. Salicylate (acetyl salicylate acid, aspirin) and intravenous immunoglobulin (IVIG) are widely used to treat Kawasaki disease, although salicylate is generally avoided in children because of concerns about serious side effects, particularly the risk of Reye's syndrome causing swelling of the brain and liver.
The review authors identified only one randomised controlled trial, from Japan, reported in 1991. A total of 102 children were randomised to receive IVIG with or without salicylate. There was no clear benefit of adding salicylate to immunoglobulin treatment on the rate of coronary artery abnormalities observed, up to 30 days. The spread of findings was wide and could include a beneficial effect of salicylate. There are theoretical grounds for using salicylate to prevent damage to the coronary arteries. However, there are concerns that aspirin use in children to treat fever can have adverse effects and children with Kawasaki disease who are treated with immunoglobulins have a very low rate of coronary artery abnormalities.