Kawasaki disease (Kawasaki syndrome) is a rare viral infection in toddlers that could lead to serious heart health complications. It mostly affects children as young as six months to five years old and needs immediate medical intervention. The most common symptoms for parents to look out for in their kids would be prolonged fever, red eyes, red throat and the appearance of red rashes all over the body including the tongue and mouth. Kawasaki disease (KD) is also known as Kawasaki syndrome and could also affect teens and adults in a slightly different manner, mainly without the symptoms on the skin.
What is Kawasaki disease?
“Kawasaki disease is an inflammatory condition of the blood vessels, especially the coronary arteries, which supply oxygen-rich blood to the heart,” explains Dr Vanita Arora, senior consultant, cardiac electrophysiologist and interventional cardiologist, Indraprastha Apollo Hospital, New Delhi. This inflammation could also affect the heart muscles and valves, Dr Arora adds.
According to an article published by the American Heart Association, KD affects children and a smaller percentage of teens, creating inflammation in the blood vessels, particularly the coronary arteries. The average age of those affected is two years. About 77 per cent are younger than five and boys are 1.5 times more likely than girls to get KD.
Kawasaki disease is named after the Japanese pediatrician Dr Tomisaku Kawasaki who first discovered it in 1961. This condition was earlier also known as mucocutaneous lymph node syndrome — as it causes the lymph nodes to become swollen due to inflammation.
According to Bengaluru-based Dr Harish C, consultant, interventional cardiology, Fortis Hospital, Bannerghatta Road, more cases of KD are being detected in recent years. “The last five to 10 years have seen an increasing number of children getting admitted with Kawasaki disease symptoms in the ICU,” he tells Happiest Health.
“Although we do not have an exact number, it is reported that the incidence is about three to four per 1,000 children younger than five years,” says Dr Rajath Athreya, senior consultant and HOD, pediatrics and neonatology, Sakra World Hospital, Bengaluru.
What causes Kawasaki disease?
Researchers are yet to exactly identify the exact reason for this condition. It is now being pointed out that KD is an extreme case of infection caused by either a virus or a bacterium triggering inflammation that manipulates the immune system.
“There may be viral triggers for it as we often see cases of Kawasaki disease clustered together in the same locality,” says Dr Athreya.
He also adds that one of the reasons for KD could be that the immune system is in hyperactive mode. The immune system activates the measures usually meant to counter viral infections, leading to severe inflammation and related complications. Dr Harish also points out that specific genetic factors could also trigger extreme inflammation in some people.
What are the symptoms of Kawasaki disease?
Experts explain the symptoms of Kawasaki disease can be quite prominent because of their physical manifestations. Some of the symptoms are:
- High and consistent fever for more than four or five days followed by an enlarged lymph node in the neck and bloodshot eyes
- Red rashes on the body and oral lesions
- Strawberry tongue (red), swollen tongue and cracked lips
- Swollen skin on the palms and soles of the feet that tends to peel off
Investigating Kawasaki syndrome
Dr Athreya says there is no one test to confirm the diagnosis, so pediatricians put together the symptoms and lab results and then draw a conclusion. If a child is suspected to be affected by Kawasaki syndrome, the initial five to 10 days are crucial to investigate whether coronary arteries have been affected or not.
“If the results show an enlarged coronary artery, then the condition is likely to cause blockage in the blood flow because of thrombosis [clotting] or it can rupture,” explains Dr Harish C.
Dr Arora also adds that inflammation of the coronary arteries could lead to the weakening and bulging of arterial walls called aneurysms. This could lead to the formation of blood clots which could either cause a heart attack or internal bleeding.
Dr Harish adds that this could cause a condition called pericardial effusion which is the accumulation of fluid around the pericardium (a sac surrounding the heart).
Also, in this condition, the platelet count tends to increase which is not always a desirable thing.
“Platelets help us form clots when we have any acute injury, but in this situation, excessive platelets can lead to occlusion [obstruction],” explains Dr Harish. So, if the heart doesn’t receive an adequate amount of blood, it starts to fail and causes a fatality.
According to a review article published in the journal Genes & Diseases, KD not only increases platelets but also activates them, thereby increasing the risk of thrombosis. Similarly, a fall in platelet counts during the acute stage of KD has also been found to be associated with increased severity of the disease.
“That’s because our body needs only an ample [specific] number of platelets – not too low nor too high,” reasons Dr Harish.
Incomplete Kawasaki disease
Experts point out that children often do not show all symptoms associated with Kawasaki disease making it difficult for a proper diagnosis. This condition is known as incomplete Kawasaki disease.
“However, even then, the slightest of suspicion should be investigated to help in the diagnosis and starting the treatment early,” opines Dr Harish.
In Dr Athreya’s observation, cases of previous or recent covid infections in a very small proportion of children have also resulted in a condition very similar to KD. “We have termed this as MISC – multisystem inflammatory syndrome in children,” he explains. He says this can be more severe than KD in the acute phase itself with some children needing intensive care. “Heart complications similar to KD are also seen,” he adds.
Treatment for Kawasaki disease
If not diagnosed timely, KD can turn into a complicated condition, however, with timely diagnosis and intervention, children are most likely to recover completely.
“KD is usually treatable and most children recover without serious problems if they receive treatment within 10 days of the onset of the symptoms,” says Dr Harish.
