Classic KD Children with at least five days of fever and at least four of the following clinical features*:  Oral mucous membrane changes, including any of the following: Erythema, dryness, and/or cracking of the lips Tongue erythema with prominent fungiform papillae (“strawberry tongue”) Diffuse oropharyngeal mucosal erythema  Bilateral, nonexudative bulbar conjunctivitis, often sparing the limbus  Diffuse, erythematous, maculopapular rash primarily affecting the trunk and extremities†  Extremity changes: hand and foot edema, erythema, and/or painful induration of the palms and soles (acute phase) or periungual desquamation (subacute phase, two to three weeks after fever onset)  Unilateral cervical lymphadenopathy (≥ 1.5 cm in diameter)	Suspected incomplete KD Children with at least five days of fever and at least two to three of the criteria for classic KD or infants with prolonged, unexplained fever (≥ 7 days)‡ who have the following findings:  Elevated erythrocyte sedimentation rate (≥ 40 mm per hour) and/or elevated C-reactive protein (≥ 3 mg per dL [30 mg per L]), and  A positive echocardiography§or three or more of the following laboratory findings: Anemia for age Thrombocytosis (platelet count ≥ 450,000 per μL [450 × 109 per L]) after day 7 of fever Hypoalbuminemia (albumin ≤ 3 g per dL [30 mg per L]) Elevated alanine transaminase level Leukocytosis (white blood cell count ≥ 15,000 per μL [15 × 109 per L]) Sterile pyuria (≥ 10 white blood cells per high-power field)
Additional comments
Because the clinical features of KD are nonspecific, physicians should consider other diagnoses with similar findings; alternative diagnoses should be sought, particularly in patients with conjunctival or pharyngeal exudates, oral ulcers, a bullous or vesicular rash, generalized lymphadenopathy, or splenomegaly. Patients with KD can have a concurrent viral infection; therefore, identification of a viral pathogen does not preclude the diagnosis of KD. Given the potential for a missed KD diagnosis and/or higher risk of coronary abnormalities, physicians should consider KD in the differential diagnosis for the following:  Infants younger than 6 months with prolonged, unexplained fever and irritability or with prolonged fever and unexplained aseptic meningitis  Patients with prolonged fever and unexplained shock that is ultimately culture-negative  Patients with prolonged fever and cervical lymphadenopathy or retro-/parapharyngeal phlegmon whose course does not respond to appropriate antibiotic treatment