How does Kawasaki disease attack the body?

Kawasaki disease, also known as mucocutaneous lymph node syndrome, is a rare condition that primarily affects young children. It causes inflammation in the blood vessels throughout the body, leading to a range of symptoms and potential complications.

The exact mechanism by which Kawasaki disease attacks the body is not fully understood, but several key processes have been identified:

1. Immune System Dysregulation: Kawasaki disease is believed to be triggered by an abnormal immune response to an infectious agent, although the specific pathogen has not been definitively identified. The immune system overreacts, leading to widespread inflammation and damage to blood vessels.

2. Vasculitis: The hallmark feature of Kawasaki disease is inflammation of the blood vessels (vasculitis). This inflammation affects small and medium-sized arteries, particularly the coronary arteries that supply blood to the heart. The inflammation can cause weakening, dilation, and narrowing of these blood vessels, leading to various symptoms and complications.

3. Endothelial Damage: The inner lining of blood vessels, known as the endothelium, is primarily affected in Kawasaki disease. The inflammation damages endothelial cells, disrupting their normal function and leading to the release of inflammatory mediators that perpetuate the vasculitis.

4. Coronary Artery Involvement: Kawasaki disease is particularly known for its potential impact on the coronary arteries. The inflammation and damage to these arteries can lead to the development of coronary artery aneurysms, which are abnormal bulges in the vessel walls. In severe cases, these aneurysms can rupture, causing life-threatening complications such as myocardial infarction (heart attack) or sudden cardiac death.

5. Multisystem Inflammation: In addition to the vascular involvement, Kawasaki disease also affects other parts of the body, leading to various symptoms. This includes fever, rash, swollen lymph nodes (particularly in the neck), conjunctivitis (inflammation of the eyes), inflammation of the mouth and tongue (strawberry tongue), and desquamation (peeling) of the skin, typically starting from the fingertips and toes.

6. Cytokine Storm: Kawasaki disease is associated with a cytokine storm, which refers to an excessive and uncontrolled release of inflammatory cytokines and other signaling molecules. This cytokine storm contributes to the widespread inflammation, fever, and other systemic symptoms.

Early diagnosis and prompt treatment with high-dose intravenous immunoglobulin (IVIg) and other medications can significantly reduce the risk of complications, such as coronary artery abnormalities, in Kawasaki disease.