Kawasaki disease

Abstract

In this chapter, the epidemiology, typical clinical manifestations, and therapy of KD are described. KD mainly affects children <5 year, is uncommon in infants <3 months, and rare in neonates and adults. Male-to-female ratio is 1:8. It is more common among Asian populations. In Japan, the annual incidence is 216.9/100,000 children aged 0–4 years; in Europe, 2.9–6.9; and in the US Caucasians, 6–9, supporting the speculation that both genetic predisposition and environmental factors are critical for KD pathogenesis. An infectious agent seems to lead to a massive stimulation of the immune system and the development of KD in a small subset of genetically predisposed individuals. The discovery of viral-like cytoplasmic inclusion bodies in ciliated bronchial epithelial cells supports the hypothesis that KD might arise from a previously unidentified ubiquitous RNA virus. KD is the leading cause of acquired heart disease in children in industrialized countries; CAA developed in about 25 % of untreated children and in 3 % of those who received IVIG. The mortality rate is 0, 14 %. Along with premature atherosclerosis, KD is a potential risk for adult ischemic heart disease and sudden death. The diagnosis relies on clinical criteria after the exclusion of other febrile diseases with rash. High fever lasting >5 days is a mandatory diagnostic criterion plus at least four of five core signs: conjunctivitis, mucositis, polymorphous rash, lymphadenopathy, changes of peripheral extremities, and perineum. In case of persistent fever and occurrence of CAA, four criteria are not required for the diagnosis. Diagnosing KD is challenging, since many common febrile diseases presenting with rash, lymph node enlargement, and pharyngeal or conjunctival erythema mimic KD. Therapy includes IVIG (2 g/Kg) by 10 days from fever onset and aspirin (50–80 mg/kg). In severe cases, a second IVIG pulse, i.v. methylprednisolone (30 mg/Kg), and anti-TNF drug are required.