Kawasaki disease (KD, formerly called mucocutaneous lymph node syndrome) is one of the most common vasculitides of childhood . KD also occurs rarely in adults. It is typically a self-limited condition, with fever and manifestations of acute inflammation lasting for an average of 12 days without therapy . However, complications such as coronary artery (CA) aneurysms may develop and lead to significant morbidity and mortality.
Children suspected of having KD who do not fulfill diagnostic criteria (ie, have fever ≥5 days, but less than four signs of mucocutaneous inflammation) may have incomplete or atypical KD [1-3]. "Incomplete KD" is the preferred term, since these patients do not appear to differ from those with classic KD in any way except that they lack a sufficient number of criteria to fulfill the epidemiologic case definition . Children with incomplete KD are also at risk for cardiovascular sequelae.
The clinical manifestations, diagnosis, and criteria for treatment of incomplete KD are discussed in this review. Unique features in infants and adults are also presented. Other aspects of KD are reviewed separately. (See "Kawasaki disease: Epidemiology and etiology" and "Kawasaki disease: Clinical features and diagnosis" and "Kawasaki disease: Initial treatment and prognosis" and "Kawasaki disease: Complications" and "Cardiovascular sequelae of Kawasaki disease".)
The incidence of incomplete Kawasaki disease (KD) is unknown [4,5]. In a retrospective report of 242 Japanese children with KD treated at a single center over a nine-year period, 10 percent of patients were diagnosed with incomplete KD . The incidence appears to be greater in infants younger than six months of age [5,6]. This was illustrated in a retrospective review of 44 children with KD. Five of 11 infants (45 percent) had incomplete disease compared with 4 of 33 (12 percent) older children . KD occurs rarely in adults and presents in an incomplete form more often than in children [7-13].
CLINICAL PRESENTATION OF TYPICAL VERSUS INCOMPLETE KD
Signs and symptoms appear to parallel those in children who fulfill diagnostic criteria for typical disease (table 1) when clinical judgment of reliable observers is used to define incomplete Kawasaki disease (KD). Fever for five or more days is the one common finding. However, fever may be absent or missed in some infants. Patients with incomplete KD have less than four signs of mucocutaneous inflammation. Some infants present only with fever and no other clinical features of KD. (See "Kawasaki disease: Clinical features and diagnosis", section on 'Clinical manifestations' and 'Infants' below.)