Causes of Kawasaki Disease

One of the most interesting parts of Kawasaki disease is that scientists still don’t know what exactly causes it. Doctors know how to recognize and treat it, but the trigger of the disease in the first place is still being studied

Its believed that KD (Kawasaki Disease) is not caused by a single virus or bacteria. Instead, the leading theory is that KD is an abnormal immune response to an infection in children who are genetically susceptible. This means that even if different children are exposed to the same infection/trigger, only some will develop KD. (merckmanuals.com)

The genetic component of KD is still being studied by researchers, but some immune related genes appear more commonly in children who develop KD. The variation in the genes could influence how strongly the immune system of a child reacts, leading to a link between immune pathway genes and increased susceptibility. This could lead to an explanation on why KD is more common in certain demographics. For example, children with East Asian descent, particularly Japanese children, have much higher rates of developing KD, even when they are not living in Japan. (sciencedaily.com)

Another hypothesis proposed by scientists is that there are specific infectious triggers that cause KD. KD often appears seasonally, especially in the winter and early spring season. This leads scientist to believe that a common infection, even one that could be mild to most children, could trigger an immune response in genetically susceptible children. (nih.gov)

Even with decades of research, there are still many unanswered questions:

Why does the disease primarily affect children under 5?

Why do only some children develop complications?

How many triggers are there?

With new technology, researchers can look for patterns in genes to explain the different responses. Computational biology and bioinformatics play a big part in identifying patterns that traditional methods may miss.

Finding the trigger to Kawasaki could improve early diagnosis and help predict which children are at higher risk, as well as develop targeted therapies and even prevent the disease in the future.

For me, learning that Kawasaki disease is likely a overreaction by the immune system, changed the way I approached the disease. At first I thought it was some very complex infection caused by some unknown virus. Now that I know its likely caused by our own immune system, it has made me more interested in how immune responses are triggered and how, sometimes, those responses can go beyond their intended purpose.