FIGURE 101.15 Evaluation of suspected Kawasaki disease KD, Kawasaki disease; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; ALT, alanine aminotransferase; WBC, white blood cell; hpf, high-powered field; echo, echocardiogram (Adapted with permission from Sundel RP Kawasaki disease: Clinical features and diagnosis In: Post TW (Ed), UpToDate Waltham, MA Accessed March 4, 2019 Copyright ©2019 UpToDate, Inc For more information visit www.uptodate.com ) No laboratory studies are included in the diagnostic criteria for KD, but certain findings may support the diagnosis Most characteristic is systemic inflammation, with widespread elevation of acute-phase reactants (including CRP and ESR), leukocytosis, and a left shift in the white blood cell count By the second week of illness, platelet counts also rise, reaching 1,000,000/mm3 in the most severe cases Thrombocytopenia is a poor prognostic factor and may indicate platelet consumption