It is characterized by an inflammation of the blood vessels (vasculitis).
Kawasaki disease, also known as mucocutaneous lymph node syndrome , was named after the Japanese pediatrician who first described it.
Kawasaki disease mainly affects preschool children under 5 years of age.
Although older children can develop the disease it is most common between the ages of 6 months and 4 years.
Kawasaki disease can be treated, and most children make a full recovery.
A small number of children develop heart problems that need long-term treatment.
Kawasaki disease causes
The etiology is unknown, but several pathogenic theories have been proposed: infection by a toxin-secreting microorganism and a superantigen-directed process.
Infection is thought to play a role in triggering an abnormal inflammatory response.
Genetics seem to play a role, as the disease is much more common in Asian populations.
Whole genome studies have identified single nucleotide polymorphisms that would confer greater susceptibility to the disease and its complications.
What is known is that Kawasaki disease is not contagious, so it cannot be passed from one child to another.
Symptoms of Kawasaki disease
They may have a fever greater than 39 ° C, which persists for more than 5 days. In general, the fever does not improve with medications such as acetaminophen or ibuprofen.
Additional typical manifestations of Kawasaki disease include limb changes such as erythema and edema of the palms and soles that peel after 2 to 3 weeks
Generally, in the subacute phase, a polymorphous rash of the skin (maculopapular, urtricarial or scarlatiniform, erythroderma or microplastic) is observed.
Lymphadenopathy (cervical, often unilateral), bilateral non-exudative conjunctivitis, and involvement of the lips and oral mucosa (erythema, strawberry tongue, lip fissures) may also be seen.
Alcoholic ketoacidosis is a life-threatening complication that occurs in the subacute phase (6 to 8 weeks after onset) in 20 to 35% of untreated children.
Atypical manifestations include myocarditis, pericarditis, valve regurgitation, hepatitis, diarrhea, abdominal pain, gallbladder hydrops, arthralgia, arthritis, myalgia, aseptic meningitis, sensorineural hearing loss, urethritis, and sterile pyuria.
Kawasaki disease complications
Kawasaki disease can cause inflammation of the heart muscle and the blood vessels that supply the heart (coronary arteries), which can be a potentially serious problem.
In about a quarter of children with untreated Kawasaki disease, inflammation of the coronary arteries can lead to the development of coronary aneurysms (a thinning of the artery wall that causes it to bulge).
Aneurysms can increase the risk of a blood clot forming in the affected artery, and in rare cases, coronary aneurysms can burst.
While aneurysms may get better on their own, some children need ongoing monitoring and treatment.
Less common complications that can affect children with Kawasaki disease include problems with the heart valves and fluid buildup around the heart.
Diagnosis and tests
If you suspect that your child may have Kawasaki disease, you should seek medical attention immediately.
The doctor will ask about your child’s symptoms and perform a physical exam, looking for signs that suggest a possible diagnosis of Kawasaki disease.
The diagnosis is clinical. While there are no specific tests that can diagnose Kawasaki disease, there are tests that can aid in the diagnosis.
Blood tests that are used to help diagnose Kawasaki disease and may include:
Complete blood count
This test may show an increase in white blood cells and / or anemia, as well as abnormally high levels of platelets in the second week of discomfort.
Erythrocyte sedimentation rate and C-reactive protein tests, which are markers of inflammation, are generally elevated in children with Kawasaki disease.
Liver function tests
Laboratory findings (elevated acute inflammatory markers, liver enzymes, neutrophilia, and thrombocytosis), although nonspecific, are supportive.
Ultrasound of the heart (echocardiography) is recommended to detect changes in the heart and coronary arteries.
Doctors generally recommend repeating this test after 6 to 8 weeks to make sure complications have not developed later in the course of the disease.
Chest X-ray is used to see if Kawasaki disease has affected the heart
The electrocardiogram is used to assess whether Kawasaki disease has affected the electrical activity of the heart.
The differential diagnosis includes autoimmune and autoinflammatory diseases (systemic lupus erythematosus, polyarteritis nodosa, and sarcoidosis).
It also includes bacterial infections (bacterial toxic shock syndrome, leptospirosis), viral infections (measles, Epstein-Barr virus), and toxins or reactions to medications.
Kawasaki disease treatment
Early diagnosis and initiation of treatment significantly reduces the risk of long-term complications.
Early administration of intravenous immunoglobulin reduces the rate of coronary abnormalities in less than 5% of patients.
Intravenous immunoglobulin is administered in a single dose of 2 g / kg (over a 24-hour period) before the 10th day of initiation.
Treatment consists of injecting high doses of antibodies into a vein through a drip: intravenous immunoglobulin.
Fever and many of the other symptoms will improve quickly with this therapy.
Immune globulin treatment also helps prevent complications of the disease from developing, particularly those that affect the heart.
In the event of treatment failure, intravenous immunoglobulin, methylprednisolone, prednisolone, and infliximab can be considered second-line treatments.
High doses of aspirin (80-100 mg per kg per day) are usually given in the febrile phase, followed by low (antiplatelet) doses of 3 to 5 mg per day) for 6 to 8 weeks.
Aspirin is also usually given to help reduce the risk of blood clots and prevent the development of coronary artery problems.
It can also help reduce inflammation. Aspirin is administered orally and is generally continued for at least several weeks.
Measles and other live virus vaccines (ie, chickenpox) should be deferred for 11 months after treatment with high-dose intravenous immune globulin.
Alternatively, a child at high risk for measles could be vaccinated and then vaccinated again at least 11 months after administration of intravenous immune globulin.
Other routine immunizations should not be interrupted. The annual flu shot is recommended for children with coronary aneurysms.
Most children with Kawasaki disease make a full recovery.
Children who develop a heart problem may need additional treatment.
These are at risk of major cardiovascular events and their long-term outcome can be complicated by premature ischemic heart disease and will require long-term follow-up with a pediatric cardiologist.