Four days of fever in a small child is the number to act on

Kawasaki disease is a rare illness that usually affects small children, also
called Kawasaki syndrome or mucocutaneous lymph node syndrome. It is a
vasculitis — inflammation of the blood vessels.

**It is serious, and most children can fully recover if they are treated right
away.** Both halves of that sentence carry weight, and together they make
timing the whole story.

The number that matters

The listed symptom is a high fever lasting at least five days. The listed
advice is different:

Contact your child's provider if your child has a fever for 4 days,
especially with any other symptom of Kawasaki disease.

Four, not five. The diagnostic threshold and the point at which to pick up the
phone are deliberately not the same number.

The other symptoms:

• A rash, often on the back, chest and groin
• Swollen hands and feet
• Redness of the lips, the lining of the mouth, the tongue, the palms and
  the soles
• Pink eye (conjunctivitis)
• Swollen lymph nodes in the neck

What it can damage

Kawasaki disease sometimes affects the walls of the coronary arteries,
which carry blood and oxygen to the heart. That can cause:

• An aneurysm — bulging and thinning of the artery walls — raising the risk
  of blood clots, which untreated can lead to a **heart attack or internal
  bleeding**
• Inflammation in the heart
• Heart valve problems

It can also affect the brain and nervous system, the immune system and the
digestive system.

Cause, and who gets it

The immune system injures the blood vessels by mistake; researchers do not
fully know why. The vessels become inflamed and can narrow or close off.
Genetics may play a role, and environmental factors such as infections may
too. It does not seem to be contagious — it cannot be passed from one child
to another.

It usually affects children under 5, though older children and adults
sometimes get it. It is more common in boys, and children of **Asian or
Pacific Islander descent** are more likely to get it.

Diagnosis and treatment

There is no specific test. A provider does a physical exam looking at the
signs and symptoms, orders blood and urine tests to rule out other diseases
and check for inflammation, and may order an echocardiogram and ECG to
check for heart damage.

Treatment is usually in hospital with an **intravenous dose of immunoglobulin
(IVIG)** — antibodies, the proteins the immune system makes to fight
infections. Aspirin may also be part of it.

Do not give a child aspirin unless the provider tells you to. Aspirin can
cause Reye syndrome, a rare and serious illness affecting the brain and
liver.

Treatment usually works. If it is not working well enough, other
anti-inflammatory medicines may be added, and where the heart is affected a
child may need additional medicines, surgery or other procedures.

Source: MedlinePlus, U.S. National Library of Medicine.