Influenza A (H1N1) pdm09 virus infection in a patient with incomplete Kawasaki disease

RATIONALE: Kawasaki disease (KD) is a vasculitic illness of childhood associated with coronary artery dilatation, coronary artery aneurysm, arrhythmia, sudden death, and other serious cardiovascular diseases. Up to date, the etiology of KD remains unclear; however, epidemiological characteristics indicate that it may be related to as-yet-undefined pathogen infection. PATIENT CONCERNS: A 19-month-old boy had a fever of unknown origin at 38°C for 9 days without rash, runny nose and cough. DIAGNOSIS: The boy was diagnosed with incomplete KD (IKD) coincident with influenza A (H1N1) pdm09 virus. INTERVENTIONS: He was received treatments including human immunoglobulin (2 g/kg), aspirin (30∼50 mg/kg.d), and dipyridamole (3∼5 mg/kg.d). OUTCOMES: After 24 hours of human immunoglobulin infusion, his body temperature returned normal. After hospitalization for 6 days, his symptoms disappeared and discharged from the hospital. LESSONS: More attention should be paid to the correlation between KD and pathogen infection, especially the new influenza virus H1N1. The potential mechanism underlying viral infection-mediated KD is worthy of further investigation, which may provide scientific evidence for the pathogenesis of KD.