[A 9-week-old boy with fever and diarrhoea].

A 9-week-year-old boy was admitted to the pediatric clinic after 12 hours of fever and diarrhoea. On admission he had a fever of 40 degrees C, rhinitis and moderate diarrhoea. Blood tests were normal, except for elevated CRP (89 mg/L). The tentative diagnosis was viral gastroenteritis, and peroral rehydration with a hypertone glucose-salt-mixture was started. CRP reached a maximum of 199 mg/L, and the boy stayed febrile throughout the next days. Stool examination revealed Enterovirus. After several clinical examinations, findings included a reactive cervical glandular node and mild conjunctivitis. When the child had been febrile for five days, he was admitted to an echocardiography, which showed dilated coronary arteries with abnormal caliber variations and a small amount of pericardial fluid. Since he fulfilled only three of the five criteria of classical Kawasaki disease, he was diagnosed as having neonatal, incomplete Kawasaki disease. Kawasaki disease is an immunologic vasculitis that appears mainly in children between three months and 12 years of age. Only 2% of patients with Kawasaki disease are less than three months old. Neonates with Kawasaki disease often have an atypical presentation of symptoms and have a particular risk of developing coronary artery aneurysms with potentially fatal outcome. With this case-report we will stress the importance of considering Kawasaki disease in neonates with fever of unknown origin.