Aspirin is necessary for Kawasaki disease. Considering the pros and cons, aspirin must be used in cases of Kawasaki disease, initially in high doses. However, aspirin indeed has side effects. Some say aspirin is contraindicated for children, as its consumption can lead to Reye's Syndrome. This syndrome involves widespread mitochondrial damage following the intake of salicylate drugs during viral infection recovery, posing risks to the liver and brain. Without timely treatment, it could likely lead to liver and kidney failure, brain damage, or even death. Thus, aside from specific diseases, the use of aspirin is strictly prohibited. These specific diseases include Kawasaki disease, rheumatoid arthritis, etc. Therefore, the use of aspirin in Kawasaki disease is necessary, but it can indeed lead to some side effects.