Kawasaki disease is an acute systemic vasculitis manifested by fever and mucocutaneous inflammation that occurs primarily in early childhood. It is currently the most common cause of acquired heart disease in childhood in the United States and other developed countries. Although features of Kawasaki disease suggest an infectious cause and a genetic predisposition is likely, the etiology of the disorder is unclear. The incidence of Kawasaki disease varies according to ethnic group, with incidence highest in Asians and Pacific Islanders and lowest in whites. Because there is no specific diagnostic test available, diagnosis is based on well-established clinical criteria as well as supportive additional findings and laboratory data. Accurate diagnosis is important, as properly initiated treatment can significantly reduce the morbidity and mortality associated with the potential cardiac sequelae.

Classic diagnosis of Kawasaki disease requires fever for 5 or more days and four or more of the five major clinical features. These features include extremity changes, rash, oral mucosal changes, bilateral nonexudative conjunctivitis, and cervical lymphadenopathy. Extremity changes are particularly distinctive and include erythema or the palms and soles in the acute period. Edema of the hands and feet may also occur; induration when present is sometimes painful. Two to 3 weeks after disease onset, patients may have desquamation of the fingers and toes beginning in the periungual region. The rash of Kawasaki disease is typically a nonspecific maculopapular rash, though urticarial, scarlatiniform, and erythema multiforme-like varieties have been described. Conjunctival injection is usually painless and begins shortly after fever onset. The bulbar region of the conjunctivae is preferentially affected. Uveitis may coexist and is typically mild. Oral mucosal changes included generalized mucosal erythema; strawberry tongue; and peeling, redness, or cracking of the lips. Of the principal features, cervical lymphadenopathy is the least common; to meet diagnostic criteria the lymphadenopathy must be >1.5 cm in diameter and is most often unilateral.