Kawasaki disease

The cause of Kawasaki disease is not fully understood, but it is thought to be caused by an infectious agent (something that causes an infection).

Infection

Kawasaki disease acts as if it is caused by an infection, which would mean that a bacteria or virus could be responsible. However, so far no viral or bacterial cause has been identified. Also, Kawasaki disease is not contagious (passed from person to person), which means it is unlikely to be caused by a virus alone.

Kawasaki disease does not usually affect babies under six months of age. This suggests that newborn babies are protected from Kawasaki disease by antibodies (proteins that destroy disease-carrying organisms and toxins) that are passed to them by their mother, either before they were born or during breastfeeding.

Most older children and adults must also have become immune to whatever causes Kawasaki disease because they are rarely affected. This suggests that many people are exposed to whatever causes Kawasaki disease, but only a few develop the symptoms.

Genetics

As only some children are affected by Kawasaki disease, it is possible that they are genetically predisposed to the condition. This means that the genes (units of genetic material) that they inherit from their parents somehow make them more likely to get Kawasaki disease.

One theory suggests that, rather than there being a single gene that causes Kawasaki disease, it may be the result of many genes that each slightly increase the chances of a child developing the condition. Research is currently underway to identify which genes may be responsible. 

Other theories

Other ideas about Kawasaki disease suggest that it may be an autoimmune disorder, when the immune system (the body’s defence system) attacks its own tissues and organs.

Other theories suggest that it is a reaction to certain medications or pollutants in the environment, such as chemicals or toxins.

Glossary

Disease
A disease is an illness or condition that interferes with normal body functions.

Bacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and some are good for you.

Antibodies
Antibodies are your body's natural defence against any foreign antigens that enter your blood. An antibody is a protein that is produced by the body to neutralise or destroy disease-carrying organisms and toxins.

Genetic
Genetic is a term that refers to genes. Genes are the characteristics inherited from a family member.

Gene
A gene is a unit of genetic material that determines your body's characteristics.

Immune system
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.