Kawasaki disease is a rare syndrome of unknown origin that affects children. It involves inflammation of the blood vessels, and it affects the arteries. It can have a serious long-term effect on the heart.
According to The Kawasaki Disease Foundation, around 80 percent of patients are under the age of 5 years. Less commonly, it affects older children and teenagers.
It does not usually affect children under 6 months, possibly because they are protected by antibodies from their mother.
In the United States, 19 children in every 100,000 are admitted to the hospital with Kawasaki disease every year.
Inflammation occurs in the walls of arteries throughout the body, including the coronary arteries, which supply blood to the heart muscle.
As it affects the lymph nodes and skin and mucous membranes inside the nose, mouth, and throat, it is also called mucocutaneous lymph node syndrome.
It is not contagious.
Signs and symptoms develop in three phases.
Acute phase, or phase 1
Symptoms appear from day 1 to 11. They emerge suddenly and are usually intense.
High body temperature, or fever, which continues for at least 5 days and may reach 104 degrees Fahrenheit or 40 degrees Celsius. The fever does not respond to over-the-counter (OTC) painkillers, such as ibuprofen or Tylenol (paracetamol)
Conjunctivitis in both eyes, where the whites of the eyes become red, and the eyes may be itchy, watery, and sore
Swollen, chapped, and dry lips
Red, swollen tongue, often with small lumps at the back, sometimes referred to as strawberry tongue
Swollen lymph glands and lumpiness on the neck
A rash on the arms, legs, and torso, and between the genitals and the anus
A second rash on the palms of the hands and the soles of the feet, which may be accompanied by peeling skin
Children who develop a rash may find it uncomfortable to move their legs.
Sub-acute, second phase
Symptoms appear from days 12 to 21. They are less severe, but they may persist for longer. The body temperature should return to normal.
Symptoms may include:
Peeling of the skin on toes and fingers
Lack of appetite
Complications are more likely to occur during this phase and the child may experience more pain and be moody.
Convalescent, or third phase
This phase lasts from about day 22 to day 60. Symptoms improve, and the patient gradually recovers until all signs of the disease are gone.
The main concern is that Kawasaki can affect the vessels around the heart so the patient must undergo evaluation with an echocardiogram.
Kawasaki disease affects the mucous membranes.
Experts do not know what causes Kawasaki disease.
One possibility is that it may be an abnormal response to a common virus that most people do not react to. Symptoms resemble those of a virus or an infection, but no specific viral or bacterial cause has been identified.
Another is that it is an autoimmune disorder, where the body’s immune system attacks its own good tissue as if it were a pathogen, or organism that causes disease.
The following may be considered risk factors for Kawasaki disease:
Age: It is more likely between the ages of 1 year and 5 years
Gender: Boys are more likely than girls to develop it
Ethnic background: People of Asian ancestry, specifically Japanese or Chinese, and Black Americans are more susceptible to Kawasaki disease
Genetics: If the parents had Kawasaki disease, their offspring may be more likey to have it, suggesting that it may be linked to an inherited gene
Environment: In the northern hemisphere, from January through March, the rate is 40 percent higher than in August through October.
Some suggest it may be a reaction to some toxins or medications, but clinical evidence is lacking.
Conjunctivitis can be a symptom of Kawasaki disease.
Changes in the lips or mouth
Enlarged lymph nodes in the neck
Rash on the body
Changes on the hands or soles of feet
Currently, no one specific test can confirm Kawasaki disease.
Since the symptoms are similar to other childhood diseases, including the measles, scarlet fever, and juvenile arthritis, some tests may be ordered to eliminate those diseases.