Kawasaki's Disease is a medium vessel vasculitis. That is an inflammation of the medium sized blood vessels in your body. We don't know what causes this but we think it was a minor infection to which your body has 'reacted' rather severely. Kawasaki's Disease can present in a number of ways but after diagnosis you may need to be seen by a cardiologist. This is because the Coronary arteries that supply blood to your heart are medium sized blood vessels which may have been affected. If they are seriously affected they can form small aneuryms (blister like swellings). These can be dangerous. A cardiologist will be able to see these on a simple scan of your child (Echocardiogram). Fortunately these swellings are rare, medication is often used early to try and reduce the chances of these aneurysms.