A 5‐year‐old boy with Kawasaki disease shock syndrome, myocarditis and macrophage activation syndrome

A 5-year-old boy presented with 20 days history of persistent high-grade fever with irritability, abdominal pain, vomiting and redness of eyes. Birth, developmental and family history were unremarkable. He had received appropriate immunisation as per the national immunisation schedule. Weight was 15 kg (−1 to −2 Z), height 117 cm (+1 to +2 Z) and head circumference 48.5 cm (−1 to −2 Z). Physical examination revealed bilateral conjunctival injection, strawberry tongue, red cracked lips, left side cervical lymphadenopathy (1.5 × 1.5 cm), perianal erythema and hepatomegaly. There was no palpable splenomegaly. Laboratory investigations revealed anaemia, neutrophilic leukocytosis, thrombocytosis (platelet count 850 × 10/L) with high C-reactive protein (106 mg/L; N < 6 mg/L), elevated erythrocyte sedimentation rate (48 mm/h), sterile pyuria and high N-terminal pro-Btype natriuretic peptide (NT-pro-BNP: 80 000; N < 125 pg/mL) (Fig. 1). Hospital course