Assessment of the outcomes of SARS-CoV-2 infection in children and young people followed at Portuguese pediatric rheumatology clinics

Introduction: Coronavirus Disease 2019 (COVID-19) generally appears to have milder clinical symptoms and fewer laboratory abnormalities in children. It remains unknown whether children and young people with inflammatory chronic diseases who acquire SARS-CoV-2 infection have a more severe course, due to either underlying disease or immunosuppressive treatments. Objectives: To assess the epidemiological features and clinical outcomes of children and young people with inflammatory chronic diseases followed at Pediatric Rheumatology Clinics who were infected with SARS-CoV-2. Methods: A multicentric prospective observational study was performed. Data on demographic variables, clinical features and treatment were collected between March 2020 and September 2021, using the Rheumatic Diseases Portuguese Register (Reuma.pt) and complemented with data from the hospital clinical records. Results: Thirty-four patients were included, 62% were female, with a median age of 13 [8-16] years and a median time of inflammatory chronic disease of 6 [3-10] years. The most common diagnoses were juvenile idiopathic arthritis (n=22, 64.7%), juvenile dermatomyositis (n=3, 8.8%) and idiopathic uveitis (n=3, 8.8%). Twenty patients were on conventional synthetic disease modifying drugs (csDMARDs) and 10 on biologic DMARDs (bDMARDs). Five patients had an active inflammatory disease at the time of infection (low activity). Seven patients had an asymptomatic infection while 27 patients (79%) had symptoms: cough (n=12), fever (n=11), rhinorrhea (n=10), headache (n=8), malaise (n=8), fatigue (n=7), anosmia (n=5), myalgia (n=5),dysgeusia (n=4), odynophagia (n=4), chest pain (n=2), diarrhea (n=2), arthralgia (n=1), vomiting (n=1) and conjunctivitis (n=1). No patient required hospitalization or directed treatment, and all recovered without sequelae. In 8 patients there was a change in the baseline medication during the infection: suspension of bDMARDs (n=4), reduction of bDMARDs (n=1), suspension of csDMARDs (n=4) and reduction of csDMARDs (n=2). Only in one patient with juvenile dermatomyositis (who discontinued bDMARDs and csDMARDs), the underlying disease worsened. Conclusions: This is the first study involving children with inflammatory chronic diseases followed at Rheumatology Clinics and SARS-CoV-2 infection in Portugal. In our cohort, mild illness was predominant, which is consistent with the literature. There was no need for hospitalization or specific treatment, and, in most cases, no worsening of the underlying disease was identified.