A 12 months old child presents with an acute febrile illness. A full blood count, ESR and blood cultures are performed and the following results noted:
Hb 90 g/l, WBC 18.6 x 109/l, Platelet count 720 x 109/l and ESR 110 mm/hr.
The blood cultures show no growth after 7 days.
The blood film shows a normochromic, normocytic anaemia with marked rouleaux formation. The neutrophils show increased granulation and vacuolation. They also show cytoplasmic swelling, a characteristic feature of Kawasaki disease. A marked thrombocytosis is present.
Could the diagnosis be sepsis or could it be Kawasaki disease?
Kawasaki disease Peripheral blood
Neutrophils showing increased granulation, vacuolation and cytoplasmic swelling
What is Kawasaki disease? In 1967, Tomisaku Kawasaki, a Japanese paediatrician, described 50 children with fever lasting for more than 5 days. The children had cervical lymphadenopathy, rash, bilateral non-exudative conjunctivitis, swelling of the hands and feet and inflammation of the oral mucosa. The children ranged in age from 6-12 months. Kawasaki disease is more common amongst males with a male-to-female ratio of 1.5:1.
The etiology of Kawasaki disease is still not understood. It is thought to be a multisystem vasculitic disorder. The onset of the fever is abrupt. It is a high, sustained fever, unresponsive to antibiotic therapy, lasting for a week or longer. During the acute phase, Kawasaki disease may cause medium and large vessel arteritis, arterial aneurysms, valvulitis and myocarditis. If untreated, approximately 20% of patients will develop coronary aneurysms. Kawasaki disease has surpassed rheumatic fever as the leading cause of heart disease in children less than 5 years of age.
The medical management of Kawasaki disease involves the use of intravenous gamma globulin as well as aspirin, which is used as an anti-inflammatory agent.
Kawasaki disease is diagnosed from a combination of clinical and haematological features. Bacterial sepsis must always be excluded. Scientists working with paediatric patients should be ever mindful of this potentially fatal disease.