Study objectives: (1) To determine those diseases that most often mimic Kawasaki disease (KD) in the United States. (2) To examine the physical findings and laboratory studies that influenced experienced clinicians to exclude the diagnosis of KD. (3) To compare epidemiologic features of patients with KD and patients referred for evaluation of possible KD in whom alternative diagnoses were established.
Design: Case comparison study.
Setting: Seven pediatric tertiary care centers.
Patients: Consecutive sample of 280 patients with KD and 42 comparison patients examined within the first 14 days after onset of fever.
Measurements and main results: (1) Infectious diseases, particularly measles and group A beta-hemolytic streptococcal infection, most closely mimicked KD and accounted for 35 (83%) of 42 patients in the comparison group. (2) The standard diagnostic clinical criteria for KD were fulfilled in 18 (46%) of 39 patients in whom other diagnoses were established. (3) Patients with KD were significantly less likely to have exudative conjunctivitis or pharyngitis, generalized adenopathy, and discrete intraoral lesions, and more likely to have a perineal distribution of their rash. The patients with KD were also more likely to have anemia and elevated erythrocyte sedimentation rate; leukocyte count less than 10 X 10(3)/mm3 and platelet count less than 200 X 10(3)/mm3 were significantly less prevalent in patients with KD. (4) Residence within 200 yards of a body of water was more common among KD patients.
Conclusions: (1) Measles and streptococcal infection should be excluded in patients examined for possible KD. (2) Laboratory studies that may be useful in discriminating patients with KD from those with alternative diagnoses include hemoglobin concentration, erythrocyte sedimentation rate, and serum alanine aminotransferase activity. (3) Residence near a body of water may be a risk factor for the development of KD.