A 7-Year-Old Boy and a 14-Year-Old Girl Initially Diagnosed with Toxic Shock Syndrome and Tested Positive for SARS-CoV-2 Infection, Supporting a Diagnosis of Multisystem Inflammatory Syndrome in Children (MIS-C).

BACKGROUND Multisystem inflammatory syndrome in children (MIS-C) has recently been described in children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This report describes 2 children with MIS-C who were initially diagnosed with toxic shock syndrome but who tested positive for SARS-CoV-2 infection on reverse transcription-polymerase chain reaction, supporting the diagnosis of MIS-C. CASE REPORT Case 1. A 7-year-old boy with fever, cough, and dyspnea was treated with oxygen, intravenous immunoglobulin (IVIG) infusion, and methylprednisolone and showed a worsening of clinical conditions, persistent fever, hypotension, and hematological parameters compatible with macrophage activation syndrome (MAS). Three intravenous boluses of methylprednisolone (30 mg/kg/day) were followed by a progressive resolution. Case 2. A 14-year-old girl with syncope, fever, diarrhea, oliguria, and increased creatinine levels required fluid infusion and correction of electrolyte imbalance. The increase of creatine phosphokinase (CPK), myoglobin, troponin, and creatine kinase-MB (CK-MB) was associated with grade I atrioventricular block and pericardial effusion. The patient showed myositis and severe muscular weakness, with hematological parameters compatible with MIS-C. She started IVIG and 3 intravenous boluses of methylprednisolone. However, bradycardia, tachypnea, severe hypotension, loss of consciousness, oliguria, bilateral ground-glass pneumonia, bilateral pleural, and peritoneal effusion, in the absence of thromboembolism, required treatment with furosemide, albumin, and enoxaparin, and was followed by a prompt resolution. CONCLUSIONS These 2 pediatric cases highlight the importance of SARS-CoV-2 testing in all patients with acute symptoms and signs of infection during the COVID-19 pandemic. As new variants of SARS-CoV-2 emerge, cases of MIS-C can become more prevalent, and pediatricians should be aware of diagnostic and management guidelines.