Oral saliva swab reverse transcription PCR for Covid-19 in the paediatric population.

OBJECTIVES: To evaluate the performance of oral saliva swab (OSS) reverse transcription PCR (RT-PCR) compared with RT-PCR and antigen rapid diagnostic test (Ag-RDT) on nasopharyngeal swabs (NPS) for SARS-CoV-2 in children. DESIGN: Cross-sectional multicentre diagnostic study. SETTING: Study nested in a prospective, observational cohort (EPICO-AEP) performed between February and March 2021 including 10 hospitals in Spain. PATIENTS: Children from 0 to 18 years with symptoms compatible with Covid-19 of ≤5 days of duration were included. Two NPS samples (Ag-RDT and RT-PCR) and one OSS sample for RT-PCR were collected. MAIN OUTCOME: Performance of Ag-RDT and RT-PCR on NPS and RT-PCR on OSS sample for SARS-CoV-2. RESULTS: 1174 children were included, aged 3.8 years (IQR 1.7-9.0); 73/1174 (6.2%) patients tested positive by at least one of the techniques. Sensitivity and specificity of OSS RT-PCR were 72.1% (95% CI 59.7 to 81.9) and 99.6% (95% CI 99 to 99.9), respectively, versus 61.8% (95% CI 49.1 to 73) and 99.9% (95% CI 99.4 to 100) for the Ag-RDT. Kappa index was 0.79 (95% CI 0.72 to 0.88) for OSS RT-PCR and 0.74 (95% CI 0.65 to 0.84) for Ag-RDT versus NPS RT-PCR. CONCLUSIONS: RT-PCR on the OSS sample is an accurate option for SARS-CoV-2 testing in children. A less intrusive technique for younger patients, who usually are tested frequently, might increase the number of patients tested.

Evolution of incidence of chilblain-like lesions in children during the first year of COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has brought innumerable reports of chilblains. The relation between pernio-like acral eruptions and COVID-19 has not been fully elucidated because most reported cases have occurred in patients with negative microbiological tests for SARS-CoV-2. METHODS: A retrospective study of 49 cases of chilblains seen during the first year of the pandemic in a children's hospital in Madrid, Spain. The incidence of these skin lesions was correlated with the number of COVID-19 admissions and environmental temperatures. Patients were separated into two groups depending on the day of onset (strict lockdown period vs. outside the lockdown period). RESULTS: Most chilblains cases presented during the first and third waves of the pandemic, paralleling the number of COVID-19 admissions. The first wave coincided with a strict lockdown, and the third wave coincided with the lowest ambient seasonal temperatures of the year. Systemic symptoms preceding chilblains were more frequent in the first wave (45.8% vs. 8.0%, p = .002), as was the co-occurrence with erythema multiforme-like lesions (16.7% vs. 0%, p = .033). Laboratory test and skin biopsies were performed more frequently in the first wave (75.0% vs. 12.0%, p < .001; and 25.0% vs. 0%, p = .007; respectively). Five patients developed recurrent cutaneous symptoms. CONCLUSIONS: An increased incidence of chilblains coincided not only with the two major waves of the pandemic, but also with the strict lockdown period in the first wave and low seasonal temperatures during the third wave. Both increased sedentary behaviors and cold environmental temperatures may have played an additive role in the development of COVID-19-related chilblains.

Dynamics of Reverse Transcription-Polymerase Chain Reaction and Serologic Test Results in Children with SARS-CoV-2 Infection.

OBJECTIVES: To determine the time to reverse transcription-polymerase chain reaction (RT-PCR) negativity after the first positive RT-PCR test, factors associated with longer time to RT-PCR negativity, proportion of children seroconverting after proven severe acute respiratory syndrome coronavirus 2 infection, and factors associated with the lack of seroconversion. STUDY DESIGN: The Epidemiological Study of Coronavirus in Children of the Spanish Society of Pediatrics is a multicenter study conducted in Spanish children to assess the characteristics of coronavirus disease 2019. In a subset of patients, 3 serial RT-PCR tests on nasopharyngeal swab specimens were performed after the first RT-PCR test, and immunoglobulin G serology for severe acute respiratory syndrome coronavirus 2 antibodies was performed in the acute and follow-up (<14 and ≥14 days after diagnosis) phase. RESULTS: In total, 324 patients were included in the study. The median time to RT-PCR negativity was 17 days (IQR, 8-29 days), and 35% of patients remained positive more than 4 weeks after the first RT-PCR test. The probability of RT-PCR negativity did not differ across groups defined by sex, disease severity, immunosuppressive drugs, or clinical phenotype. Globally, 24% of children failed to seroconvert after infection. Seroconversion was associated with hospitalization, persistence of RT-PCR positivity, and days of fever. CONCLUSIONS: Time to RT-PCR negativity was long, regardless of the severity of symptoms or other patient features. This finding should be considered when interpreting RT-PCR results in a child with symptoms, especially those with mild symptoms. Seroprevalence and postimmunization studies should consider that 11 in 4 infected children fail to seroconvert.

Clinical spectrum of COVID-19 and risk factors associated with severity in Spanish children.

We aimed to identify the spectrum of disease in children with COVID-19, and the risk factors for admission in paediatric intensive care units (PICUs). We conducted a multicentre, prospective study of children with SARS-CoV-2 infection in 76 Spanish hospitals. We included children with COVID-19 or multi-inflammatory syndrome (MIS-C) younger than 18 years old, attended during the first year of the pandemic. We enrolled 1200 children. A total of 666 (55.5%) were hospitalised, and 123 (18.4%) required admission to PICU. Most frequent major clinical syndromes in the cohort were mild syndrome (including upper respiratory tract infection and flu-like syndrome, skin or mucosae problems and asymptomatic), 44.8%; bronchopulmonary syndrome (including pneumonia, bronchitis and asthma flare), 18.5%; fever without a source, 16.2%; MIS-C, 10.6%; and gastrointestinal syndrome, 10%. In hospitalised children, the proportions were 28.5%, 25.7%, 16.5%, 19.1% and 10.2%, respectively. Risk factors associated with PICU admission were age in months (OR: 1.007; 95% CI 1.004 to 1.01), MIS-C (OR: 14.4, 95% CI 8.9 to 23.8), chronic cardiac disease (OR: 4.8, 95% CI 1.8 to 13), asthma or recurrent wheezing (OR: 2.5, 95% CI 1.2 to 5.2) and after excluding MIS-C patients, moderate/severe liver disease (OR: 8.6, 95% CI 1.6 to 47.6). However, asthmatic children were admitted into the PICU due to MIS-C or pneumonia, not due to asthma flare.Conclusion: Hospitalised children with COVID-19 usually present as one of five major clinical phenotypes of decreasing severity. Risk factors for PICU include MIS-C, elevation of inflammation biomarkers, asthma, moderate or severe liver disease and cardiac disease. What is Known: • All studies suggest that children are less susceptible to serious SARS-CoV-2 infection when compared to adults. Most studies describe symptoms at presentation. However, it remains unclear how these symptoms group together into clinically identifiable syndromes and the severity associated with them. What is New: • We have gathered the primary diagnoses into five major syndromes of decreasing severity: MIS-C, bronchopulmonary syndrome, gastrointestinal syndrome, fever without a source and mild syndrome. Classification of the children in one of the syndromes is unique and helps to assess the risk of critical illness and to define the spectrum of the disease instead of just describing symptoms and signs.

Mucocutaneous manifestations in children hospitalized with COVID-19.

BACKGROUND: Cutaneous manifestations in hospitalized children with SARS-CoV-2 have not been studied systematically. OBJECTIVE: To describe the mucocutaneous involvement in pediatric patients with COVID-19 admitted to a pediatric institution in Madrid (Spain), located in a zone reporting among the highest prevalence of COVID-19 in Europe. METHODS: A descriptive, analytical study was conducted on a series of 50 children hospitalized with COVID-19 between March 1, 2020, and November 30, 2020. RESULTS: Twenty-one patients presented with mucocutaneous symptoms: 18 patients with macular and/or papular exanthem, 17 with conjunctival hyperemia, and 9 with red cracked lips or strawberry tongue. Eighteen patients fulfilled criteria for multisystem inflammatory syndrome in children. Patients with mucocutaneous involvement tended to be older and presented to the emergency department with poor general status and extreme tachycardia, higher C-reactive protein and D-dimer levels, and lower lymphocyte counts than patients without skin signs. Mucocutaneous manifestations pose a higher risk of admission to the pediatric intensive care unit (odds ratio, 10.24; 95% confidence interval, 2.23-46.88; P = .003). CONCLUSIONS: Children hospitalized with COVID-19 frequently had mucocutaneous involvement, with most symptoms fulfilling criteria for multisystem inflammatory syndrome in children. Patients with an exanthem or conjunctival hyperemia at admission have a higher probability of pediatric intensive care admission than patients without mucocutaneous symptoms.

Severe SARS-CoV-2 Infection in Children With Suspected Acute Abdomen: A Case Series From a Tertiary Hospital in Spain.

We describe 5 children with severe SARS-CoV-2 infection, hemodynamic instability and suspected acute abdomen. This form of the disease has not been previously documented. Four of the cases were confirmed SARS-CoV-2 infection and 1 probable. All of them were previously healthy and needed a pediatric critical care unit admission. The respiratory symptoms were not dominant or were absent. Also, fever was observed. Laboratory testing revealed lymphopenia and high levels of C-reactive protein and procalcitonin with D-dimer, ferritin and interleukin-6 usually elevated. Respiratory support and inotropic support were almost always necessary. In all of them, deterioration occurred on the day of admission.

Erythema multiforme-like lesions in children and COVID-19.

During examination of cases of chilblains in children and adolescents, we identified four patients who also showed skin lesions similar to erythema multiforme (EM). They had no other known triggers for EM. One of them had a positive PCR for SARS-CoV-2, while the other three were negative. Skin biopsies from two patients showed features not typical of EM, such as deep perivascular and perieccrine infiltrate and absence of necrosis of keratinocytes. Immunohistochemistry for SARS-CoV/SARS-CoV-2 spike protein showed granular positivity in endothelial cells and epithelial cells of eccrine glands in both biopsies. All patients had an excellent outcome, and had minimal or no systemic symptoms. The coincidence of EM, a condition commonly related to viruses, and chilblains in the setting of COVID-19, and the positivity for SARS-CoV/SARS-CoV-2 spike protein by immunohistochemistry strongly suggest a link between EM-like lesions and SARS-CoV-2.

Chilblains in children in the setting of COVID-19 pandemic.

BACKGROUND: Different skin manifestations of COVID-19 are being reported. Acral lesions on the hands and feet, closely resembling chilblains, have been recognized during the peak incidence of the COVID-19 pandemic. MATERIAL AND METHODS: A retrospective review of 22 children and adolescents with chilblain-like lesions seen over a short period of time in the Emergency Department of a children's hospital during the peak incidence of COVID-19 in Madrid, Spain. RESULTS: All patients had lesions clinically consistent with chilblains of the toes or feet, with three also having lesions of the fingers. Pruritus and mild pain were the only skin symptoms elicited, and only 10 had mild respiratory and/or GI symptoms. None had fever. Coagulation tests, hemogram, serum chemistry, and lupus anticoagulant were normal in all patients tested. One out of 16 tested cases had elevated D-dimer results, but without systemic symptoms or other laboratory anomalies. SARS-CoV-2 PCR tested in 19 cases was positive in just one case. Skin biopsies obtained in six patients were consistent with chilblains. On follow-up, all cases showed spontaneous marked improvement or complete healing. CONCLUSION: Acute chilblains were observed during COVID-19 pandemic in children and teenagers. It is a mildly symptomatic condition with an excellent prognosis, usually requiring no therapy. Etiopathogenesis remains unknown.