Clinical and experimental pediatrics | 2021
Multisystem inflammatory syndrome in children and Kawasaki disease in infants: 2 sides of the same coin?
Abstract
To the editor, The world has been plagued by the novel severe acute respira\xad tory syndrome coronavirus 2 (SARS\xadCoV\xad2) causing the global pandemic of coronavirus disease 2019 (COVID\xad19). A new dis\xad ease entity, called multisystem inflammatory syndrome in children (MIS\xadC), emerged in late April to early May 2020, affected clu\xad sters of children in Europe and North America, and showed a temporal association with SARS\xadCoV\xad2 infection. This article presents an infant with MIS\xadC and features of Kawasaki disease shock syndrome (KDSS) who was treated in a tertiary hospital in Sabah, Malaysia. This study aimed to assess the labo ratory and clinical characteristics of MIS\xadC in infants, along with its simil\xad arities and differences with Kawasaki disease (KD). A healthy 4\xadmonth\xadold girl was diagnosed with SARS\xadCoV\xad2 infection. One month after being diagnosed, she presented with fever, vomiting, rash, bilateral nonpurulent conjunctivitis, dry fissured red lips, and poor feeding. She went into shock 12 hours after admission and was transferred to the pediatric intensive care unit for invasive mechanical ventilation. Her white blood cell count was 5.8×103/μL (absolute lympho\xad cyte count, 1.5×103/μL), her platelet count was 65×103/μL, and she had hypoalbuminemia (24 g/L). Her inflammatory markers were elevated: C\xadreactive protein, 102.6 mg/L; and ferritin, 504 ng/mL. She had a deranged coagulation profile (prothrombin time, 17 seconds; activated partial thromboplastin time, 75.1 seconds; international normalized ratio, 1.45) and an elevated D\xaddimer level (2.3 μg/mL). Her chest radiography findings were normal. She had an unremitting fever of up to 39.7°C daily. She was hypotensive and required intravenous (IV) adrenaline and nora\xad drenaline. Given this constellation of findings, she received IV immunoglobulin (IVIG) 1 g/kg/dose for 2 days, IV methylpredni\xad solone 2 mg/kg daily for 5 days, and oral prednisolone. She was also empirically treated with IV piperacillin\xadtazobactam, which was discontinued after the blood culture result was negative. No virus was detected in the respiratory multiplex panel. Her serum SARS\xadCoV\xad2 antibody test results were positive for Ig G. On day 4 of hospitalization, her fever subsided after completion of IVIG therapy. Echocardiography revealed normal coronary arteries and a minimal pericardial effusion. She was weaned off of the vasopressors and extubated on day 7 of hospitalization. Oral aspirin and subcutaneous enoxaparin were administered to treat thrombocytosis. The patient was discharged 19 days after hospitalization. Follow\xadup echocardiography 1 month later re\xad vealed normal coronary arteries and resolved pericardial effusion. We compared 5 infants from published case reports in PubMed, who fulfilled case definitions for MIS\xadC of the Centers for Dis\xad ease Control1) or World Health Organization2) with our case de\xad scribed above.3\xad7) These cases were further analyzed to determine if they fulfilled the diagnostic criteria for KD, incomplete KD, or KDSS (Table 1). None of the infants had any underlying comorbidity except for infant 2, who was born prematurely (gestational age, 26 weeks); had chronic lung disease, swallowing difficulty, and peri\xad ventricular hemorrhage; and had recently undergone a surgical gastrostomy procedure.3) All infants presented with persistent fever for at least 3\xadday duration. Among the infants that fulfilled the diagnostic criteria of KD or incomplete KD, the most consis\xad tent features were rash and conjunctival injection. All but infant 2 received IVIG; this was the only infant who died. MIS\xadC is a new disease entity with a heterogeneous clinical presentation. It seems to predominantly affect older children, whereby the median age reported was 7–9 years.8,9) The majority of the above infants (5 of 6, 83%) presented with features con\xad sistent with KD, incomplete KD, or KDSS with prominent mucocutaneous features (rashes, cracked lips, and conjunctival injection) and cardiovascular involvement. These 5 infants were aged between 2 and 6 months in contrast to the mean age at pre\xad sentation of typical KD of 3.4 years.10) It is important to note that typical KD is rarely reported in infants younger than 6 months of age. Furthermore, most MIS\xadC series reported male\xadto\xadfemale ratios of approximately 1.5:1, but there was a female preponde\xad rance of 2:1 in this cohort. Multisystemic involvement, especially of the gastrointestinal and cardiovascular systems with shock, was more prominent in MIS\xadC than in typical KD. Inflammatory markers were markedly elevated in contrast to typical KD.8) Moreover, MIS\xadC shows many similarities to KDSS, a rare form of KD. An important prerequisite for the diagnosis of MIS\xadC is expo\xad sure to SARS\xadCoV\xad2, confirmed by a positive reverse transcrip\xad tion\xadpolymerase chain reaction (RT\xadPCR), antigen, or serology test. Past or previous infections were identified in most MIS\xadC