Kawasaki syndrome • Vascular inflammation in children

Kawasaki syndrome is a rare inflammation of the vessels in young children, which usually heals completely, but can also have serious consequences. Everything about symptoms, treatment, possible late effects and the discussed connection with the novel coronavirus SARS-CoV-2.

In Kawasaki syndrome, the most typical symptom is fever that lasts for several days.
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At a glance:

Identify teething problems with these pictures

Identify teething problems with these pictures

What is Kawasaki syndrome?

Kawasaki syndrome is a rare, worldwide inflammatory vascular disease that in most cases occurs in children up to the age of five. In the worst case, the coronary arteries can be affected. It is very rare in Germany, and it is most common in Japan. Adults are extremely rarely affected.

Currently (as of May 14, 2020), children who have been infected with the novel coronavirus SARS-CoV-2 rarely develop inflammatory reactions that are similar to Kawasaki syndrome. The disease is named after the Japanese Kawasaki, who first described it in 1967.

Corona viruses as the cause?

The cause of Kawasaki syndrome is still unclear. An overreaction of the immune system to actually harmless respiratory infections is suspected. The possible triggers are rhinoviruses, the respiratory syncytial virus (RSV) and the harmless corona viruses 229E, HKU1, NL63 and OC43. Even after infection with the novel SARS-CoV-2 coronvirus in young children, the typical symptoms of Kawasaki syndrome have occurred in isolated cases.

Symptoms of Kawasaki syndrome

The main symptom of Kawasaki syndrome is high fever up to 40 ° C, which persists for at least five days and does not respond to antibiotics. The children are usually visibly seriously ill and weakened. At least four of the other five typical symptoms appear, usually one after the other and not simultaneously:

  • inflammation of the eyes on both sides (conjunctivitis)
  • Changes in the lips and oral cavity: redness, cracks, swelling and strawberry tongue as in scarlet fever
  • Swelling (edema) and redness on the hands and feet, later scaling of the skin on the fingertips and toes
  • non-itchy rash (rash), mostly concentrated on the trunk
  • mostly one-sided swelling of the lymph nodes on the front of the neck (firm and painful)

These symptoms can be completely absent in babies.

Diagnosis of Kawasaki syndrome

Because of the typical symptoms (fever and appearance of four of the five symptoms mentioned above), Kawasaki syndrome is suspected. Even if no other cause can be found in a visibly sick infant with a fever that persists for more than seven days, Kawasaki syndrome should be considered.

Echocardiography is always part of the diagnosis in order to rule out involvement of the coronary arteries or to detect and treat them at an early stage.

A blood test is also done. In Kawasaki syndrome, the C-reactive protein (CRP) is increased and the blood sink (BSG) is accelerated. Other blood tests, such as liver tests, may also be abnormal. The abdominal organs, lymph nodes and blood vessels can be assessed with an ultrasound examination.

Treatment for Kawasaki syndrome

In order to prevent long-term damage, early diagnosis and therapy of Kawasaki syndrome is important. The standard of therapy today is the administration of antibodies (immunoglobulins) to relieve inflammation and to regulate the overreacting immune system. In addition, acetylsalicylic acid (ASA) is given to lower the fever and to inhibit blood clotting.

If the coronary arteries are already affected by the inflammation or if there are risk factors for this, glucocorticoids (cortisone) are administered to contain the inflammation and prevent damage to these vessels.

Risk factors for coronary artery involvement are:

  • Age of the child under one year or over seven years
  • male gender
  • eye-catching laboratory values
  • Duration of the disease up to the start of therapy up to four days or over 14 days

Cortisone is used even if the sick child is not feeling better one or two days after the administration of immunoglobulins and ASA.

If the coronary arteries are affected, a cardiac catheter, balloon dilation or a stent may be necessary. In the worst case, which is extremely rare, a heart transplant must be done.

Kawasaki syndrome: course and late effects

The further course of Kawasaki syndrome depends on whether the coronary arteries in the child were affected or not. If these are inflamed, there is a higher risk of long-term consequences in the form of coronary heart disease (CHD). Therefore, follow-up examinations in pediatric cardiology should be carried out. Children at risk must be treated with ASA for a long time.

Children receiving long-term treatment with acetylsalicylic acid are at higher risk of developing Reye's syndrome if they are infected with influenza (flu) or chickenpox. You should therefore be annually against flu and should be vaccinated against chickenpox.

Adults who had Kawasaki syndrome as children should take special care to avoid risk factors for CAD, such as obesity and smoking.

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