Although viral infections and Kawasaki disease share similar symptoms, physicians shouldn’t rule out Kawasaki disease when a viral infection is also detected, as these infections may accompany the disease, suggests a new study.
Kawasaki disease (KD) is a rare condition in children that involves inflammation of the blood vessels. Symptoms often begin with high-grade fever that lasts for at least five days and is unresponsive to over-the-counter medication. Kawasaki disease represents the most common cause of acquired heart disease in children in the developed world, as the inflammation can affect a patient’s coronary arteries and heart.
Currently, no test exists to diagnose KD, so physicians must rely on clinical characteristics and exclusion of other illnesses that could mimic the disease in order to accurately diagnose a child with this condition. “Kawasaki disease and many viral infections share similar characteristics,” said Asuncion Mejias, MD, principal investigator in the Center for Vaccines and Immunity at The Research Institute at Nationwide Children’s Hospital and the study’s senior author.
This fact suggests that KD may have an infectious origin. “Multiple studies have evaluated the role of various infectious pathogens as potential causes of KD,” said Dr. Mejias. “However, despite more than 40 years of research, the cause of KD remains unknown.”
In order to determine the frequency and the clinical impact of respiratory viral infections in children diagnosed with KD, Dr. Mejias’ team examined the records of 394 patients diagnosed with KD during a 10-year period, 63.7 percent of who received viral testing. Patients who tested positive for a respiratory virus were compared with patients who tested negative for those viruses to determine whether differences existed regarding age, sex, race, clinical presentation, disease course, response to treatment, lab results or echocardiographic findings.
Of the 251 KD patients who received viral testing, 8.8 percent tested positive for a respiratory virus. There were no significant demographic differences between KD patients with viral infections and those who tested negative for viruses. Children with KD and an accompanying viral infection were diagnosed significantly more often with incomplete KD. It was also more likely that their echocardiogram would reveal signs of a dilated coronary artery.
“Standard treatment of Kawasaki disease is intravenous immunoglobulin (IVIG) and treatment must be started as soon as the diagnosis is made to prevent damage to the coronary arteries and heart,” said Dr. Dr. Mejias. “Our results underscore the need for considering IVIG therapy in children with a high suspicion of KD even in the absence of all classic symptoms and with documented respiratory viral infections.”
Although this study showed that the detection of a respiratory virus was not uncommon in children with KD, researchers did not find a predominant virus associated with the disease. “Overall, our study suggests that the presence of a concomitant viral infection should not exclude the diagnosis of KD,” said Dr. Mejias.