A child with a severe multi-system inflammatory syndrome following COVID-19 infection

Introduction: Despite the mild clinical course during the acute phase of COVID-19 infection in children, latest ongoing researches are pointing the attention towards a hyperinflammatory shock in pediatric patients as a possible consequence to COVID-19 exposure Objectives: We report the case of a child with a severe systemic inflammatory syndrome following an asymptomatic COVID-19 infection Methods: A 9-year-old male was admitted to the Pediatric Emergency Unit due to fever and abdominal pain Symptoms started 7 days before admission, with fever, vomiting and non-bloodydiarrhea Family history revealed that the father had been admitted to a COVID-19 Sub-Intensive Unit with bilateral interstitial pneumonia until 7 days before the onset of symptoms in the child On the basis of familial history and because of the presence of fever, patient entered the COVID-19 pathway and was isolated He had no chronic underlying disease nor history of previous hospitalization At admission, he appeared stable Body temperature was 38 1°C, O2 saturation was 98% in ambient area, blood pressure was 106/60 mm Hg, heart rate was 140 bpm, respiratory rate was 21 breaths per minute On examination he was alert, there were no cough, runny nose or other respiratory symptoms No conjunctivitis, rash or peripheral edema was detected He had mild hepatomegaly Results: The patient underwent blood and microbiological exams including blood specimens for cultures and nasopharyngeal swabs for SARS-COV2 nucleic acid (by RT-PCR-assay) At baseline, leukocytosis with neutrophilia and relative lymphopenia were found Hemoglobin was below the normal range, while platelets count was normal Inflammatory markers were strongly elevated, particularly CRP(420 8 mg/L), ferritin(4488 ng/mL), D-dimer(5106 ng/mL) Several significantly altered parameters suggested liver function abnormality, with hypertransaminasemia, acute renal injury, with elevated blood urea nitrogen and serum creatinine, and myocardial injury, with elevated high sensitivity cardiac troponin (434 ng/L) and brain natriuretic peptide (825 pg/mL) Lymphocyte subsets were within the normal range, while NK cells were slightly reduced Patient was also tested for respiratory syncytial virus (RSV) and for influenza viruses A and B, resulted all negative Bacteria and fungi blood cultures were sterile, as well as urine and stool cultures He was tested for COVID-19 antibodies which showed positivity of both IgG and IgM (qualitative test), confirmed by a quantitative analysis which showed a high level of IgG (5066 AU/ml) and a weak positivity of IgM (0 532 AU/mL) Echocardiography showed no ventricular dysfunction, no dilatated coronaries or pericoronary iperechogenicity Chest CT on the 2nd day showed two small bilateral areas of atelectasis associated to minimal pleural effusion more evident on the right side The diagnosis of Hyperinflammatory syndrome COVID-19 related was made Conclusion: Because of the high levels of BNP and troponin, IV methylprednisolone (5 mg/kg/day) and subcutaneous heparin (100 U/kg/day) were started after 24 hours since admission Search for COVID-19 on nasopharyngeal swabs collected for 3 consecutive days resulted negative, The patient gradually recovered and fever disappeared after 48 hours He presented no vomiting or diarrhea during the hospital stay, nor respiratory symptoms Laboratory exams dramatically improved According to his clinical and laboratoristic improvement, methylprednisolone was tapered to 3mg/kg/day and he started oral prednisone 1 25 mg/Kg/day four days after He was discharged with steroid and heparin therapy and a close follow-up was planned