Kawasaki disease is a febrile illness of children resulting in inflammation of medium sized vessels. It has surpassed rheumatic fever and become the leading cause of acquired heart disease in children in the United States. It is also known as infantile periarteritis nodosa and mucocutaneous lymph node syndrome. The disease has been named after Dr. Tomisaku Kawasaki who was the first one to describe it. The disease primarily affects children less than 10 years (90-95%) and more commonly affects children less than 5 years of age (85-90%).
Can Kawasaki Disease Go Away By Itself?
Although, Kawasaki disease goes away on its own without treatment, there are higher chances of developing coronary artery aneurysm, in approximately 25% cases, which is reduced to around 3-5% when appropriate treatment is given. Diagnosis of Kawasaki disease also reduces the chances of missed cardiac abnormalities and sudden myocardial infarction, undetected aneurysm rupture and sudden death. Therefore, it is imperative to seek treatment when suffering from Kawasaki disease and also to seek medical attention when a child suffers from uncompromising prolonged fever that does not resolve with paracetamol. (1)
The etiology of the disease remains unknown, but there is a strong implication of infection and genetic factors. Although, the disease is recognized all over the world, it is more common in Asian subcontinent, specifically in Japan and South Korea. It is 10 times more common in Japan than in United States. Kawasaki disease has male predilection, with a ratio of 1.5:1 when compared to girls.
Characteristics Of Kawasaki Disease
The disease can be divided into two types, complete and incomplete. Complete Kawasaki disease is diagnosed when fever is present for at least 5 days along with 4-5 primary characteristics and incomplete Kawasaki disease is diagnosed in the presence of fever along with at least 3 primary characteristics of the disease. The primary clinical features of the disease include bilateral bulbar conjunctivitis, extremity changes (erythema of palms and soles, desquamation of fingers and toes), diffuse maculopapular skin rash, oropharyngeal changes (diffuse erythema, strawberry tongue, fissuring/bleeding of lips), unilateral cervical lymphadenopathy (lymph node size of at least 1.5 cm).
The clinical course of the disease can be basically divided into three stages (acute, subacute and convalescent), while some authors also add a fourth chronic stage.
Acute stage is a stage in which there is a sudden onset of high grade fever (102-104 degree F) that lasts for around 1-2 weeks. The fever is non-responsive to antipyretics; however with therapy with IVIG it subsides within 3 days. If left untreated, the fever may last up to a month. Other symptoms of acute phase include irritability, otitis media, anterior uveitis, perianal erythema or desquamation, pneumonitis, pericarditis, myocarditis, urethritis, vulvitis and aseptic meningitis.
Subacute stage starts when the fever has subsided and can continue beyond one month to one and a half month. This stage is characteristic of desquamation of toes and fingers along with thrombocytosis, arthralgia/arthritis, anorexia, conjunctival injection, persistence irritability and development of coronary artery aneurysm. Risk of sudden death is greatest in this phase. If fever persists there is a greater chance of cardiac complication.
In convalescent stage, there is complete resolution of the clinical features of the disease; however, cardiac abnormalities still persist. Smaller coronary artery aneurysm resolve on their own, but large aneurysm may increase in size and there is a risk for myocardial infarction. In patients whose echocardiogram was normal earlier, there is less likelihood for new aneurysms to develop after 2 months of the disease.
The duration of chronic stage lasts lifetime and it is of clinical relevance for only people who have developed cardiac complications as the aneurysm (whether diagnosed or undiagnosed) formed as a child may rupture when adult.
Kawasaki disease usually does not recur once the initial illness has resolved. In Japan and America, the recurrence rate is approximately 3% and 1% respectively. There are higher chances of recurrence in younger children and those who had cardiac abnormalities.