Among 17 patients (8 male; median age, 8 years [range, 1.8-16 years]), most were white (n = 12) and previously healthy (mild asthma in 3).

All patients had fever (median duration, 5 days). Fourteen had gastrointestinal symptoms, with 1 showing acute ileocolitis on imaging. Mucocutaneous findings were common (rash [n = 12], conjunctivitis [n = 11], and lip redness/swelling [n = 9]). Three patients were hypoxic at presentation, and 13 had shock. Fourteen had abnormal chest radiograph findings, most commonly bilateral, interstitial opacities. Eight met criteria for KD and 5 for incomplete KD.

Levels of inflammatory markers were elevated in all patients, and most had lymphopenia (n = 12), bandemia (n = 11), elevated troponin T level (n = 14), and elevated NT-proBNP level (n = 15). Studies suggesting co-infections were infrequent (n = 3) (Table 2). Serum IL-6 level was elevated in 16. Cytokine profiling in 8 patients showed elevated IL-2R, IL-18, and CXCL 9 levels in all and mildly increased IFN-γ (n = 3) and IL-8 (n = 2) levels in some. TNF-α, IL-1b, Il-2, IL-4, IL-5, and IL-13 levels were normal. Fifteen patients required pediatric intensive care unit admission; vasoactive support was required in 10. Of 9 patients with hypoxia, none required mechanical ventilation.