Kawasaki disease (Kawasaki syndrome, mucocutaneous lymph node syndrome) is a systemic vasculitis of unknown etiology that primarily affects infants and children. Symptoms include a fever lasting more than 5 days, macular-papular erythematous rash, adenopathy, bilateral conjunctival injection and swelling of the hands and feet.
Most cases of Kawasaki begins with the onset of prolonged fever as the children are brought for medical care after unrelenting fever. For cases to be definitively diagnosed, the fever is expected to have at least lasted for 5 days before medical reporting.
In affected children, there is a higher case of irritability than should be expected of fever of the magnitude often presnted. The fever may continue in the midst of antibiotic therapy for other conditions suspected earlier.
Many parents often suggest an abrupt onset of the fever symptoms. Some non-specific symptoms follow the onset of fever . In order of decreasing frequency, the symptoms that have been noted in the past include the following:
There are no specific laboratory tests for diagnosing the Kawasaki disease. However, diagnosis is dependent on the occurrence of certain abnormalities commonly seen at various stages of the disease. At first, acute-phase reactants (ie, C-reactive protein levels (CRP) erythrocyte sedimentation rate (ESR), and alpha1-antitrypsin levels) are often elevated. They often return to baseline between 6 and 10 weeks after the onset of the illness .
In the acute stage of the disease, mild-to-moderate normochromic anaemia is seen following complete blood counts (CBCs).
Children with Kawasaki disease are cared for as inpatients on paediatric/paediatric cardiology units and then put on bed rest. This is as a result of risk of myocardial events .
The major foundation of the managing the condition is the use of intravenous immunoglobulin (IVIg) and aspirin to reduce fever, myocardial inflammation and also prevent or reduce cardiac sequelae which is often the major cause of morbidity and mortality associated with this illness.
If treatment is prompt, prognosis is good. There is a dearth of data but in the United States, death is recorded in less than 1% of children infected . In children younger than younger than a year, the death rate is approximately 4%. For those aged 1 year and older, the death rate is approximately less that 1%. On average, the mortality rate in Japan is between 0.1-0.3%. The highest mortality cases are seen 15-45 days after fever kicks in. Till today, there are no cases of adult death as a result of Kawasaki disease.
The etiology of the Kawasaki disease is still unclear. However, immunologic and epidemiologic evidence suggest a causative agent that is infectious . Genetic predisposition and autoimmune reactions are possible etiological factors that have been suggested as well.
Kawasaki disease is believed to have an infectious etiology because there is record of consistence occurrence of epidemics especially in spring and in late winter. The epidemics occur at 3 year intervals and there is a wide geographic spread of the epidemics when they occur. Other causes of suspicion of infectious etiology include adenopathy, eye signs, characteristic fever and the self-limited nature of the disease.
It is also believed that maternal antibodies may provide passive immunity as the condition is unusual among infants younger than 4 months of age. With all the infectious etiology suspicions, epidemiologic data suggests that person-to-person transmission of the disease is very much unlikely.
The highest annual incidence of the Kawasaki disease is seen in Japan with 120-180 cases reported for children aged 5 years and under. The incidence of this condition is on the rise each year in the country .
In Europe, surveys show that there is a peak annual incidence of 90 cases for every 100,000 children of Asian descent aged 5 years and below.
Statistical analysis of hospital records in England show an incidence of 8 cases amongst 100,000 children aged 5 and below.
In the USA, the incidence is 9.1 cases per 100,000 children of white descent and 32.5 cases per 100,000 children of Asian and Pacific Island descent.
Even with the visible mucocutaneous clinical findings that the disease is defined with, the disease is still regarded best as generalised vasculitis involving small arteries and medium sized arteries in some cases. The vascular inflammation seen with the disease is most common in the coronary vessels but the vasculitis is also present in capillaries, small arterioles and the larger arteries.
In the early stages of the Kawasaki disease, the endothelial cells and the vascular media become edematous with the internal elastic lamina remaining intact. 7-9 days after fever kicks in, there is an influx of neutrophils and this is almost immediately followed by a proliferation of immunoglobulin A–producing plasma cells and CD8+ (cytotoxic) lymphocytes .
A concomitant progressive increase in the serum platelet count brings about the greatest vascular damage. When the illness progresses to this stage, the risk of death is very significant.
Kawasaki disease can't be prevented.
Kawasaki disease is a self-limiting systemic vasculitis often regarded as idiopathic. It is seen mostly in children between 6 months and 5 years of age . The condition is seen mostly among the general Asian population with China and Japan posting the greater numbers. However, Kawasaki disease has been reported around the world.
A Japanese paediatrician named Tomisaku Kawasaki was the first to describe the case in 1967. The disease was not described until the 1950s so it is thought to be a relatively new disease.
Originally, the condition was regarded as a benign illness that troubles patients suffering from it a great deal but it was discovered later that its complication of the coronary artery aneurysm formation was a major cause of death and significant morbidity . Kawasaki is now the most common cause of heart disease in children, taking over from rheumatic fever. Before the delineation of the disease, cases of it were regarded as periarteritis/polyarteritis nodosa. To reduce its attendant complications, early diagnosis is recommended.
Kawasaki disease is a condition that affects the walls of the medium sized arteries in the body. It also involves the artery that is responsible for supplying blood to the heart muscle. The disease can also affect the skin and the membranes found inside the mouth, throat and nose.
This condition is rare and is seen in children the most especailly those in Japan or have Asian ancestry.
Fortunately, Kawasaki can be treated and most of the time children affected with the condition recover from it without any problems in the future.
There is no way to prevent the disease but the chances of an individual developing it is very low as long as they don't have any Asian roots.