Some clusters of children with a multisystem inflammatory syndrome (MIS-C) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported. We describe the epidemiological and clinical features of children with MIS-C in Spain. MIS-C is a potentially severe condition that presents in children with recent SARS-CoV-2 infection.

Kawasaki disease (KD) is an acute self-limited systemic vasculitis of unknown etiology affecting mainly children less than 5 years of age. Risk factors for cardiac involvement and resistance to treatment are insufficiently studied in non-Japanese children. This study aimed to investigate the epidemiology, clinical features and risk factors for resistance to treatment and coronary artery lesions (CAL) in KD in Spain. Retrospective study (May 2011-June 2016) of all patients less than 16 years of age diagnosed with KD included in KAWA-RACE network (84 Spanish hospitals). A total of 625 cases were analyzed, 63% were males, 79% under 5 year-olds and 16.8% younger than 12 months. On echocardiographic examination CAL were the most frequent findings (23%) being ectasia the most common (12%). Coronary aneurysms were diagnosed in 9.6%, reaching 20% in infants under 12 months (p<0.001). A total of 97% of the patients received intravenous immunoglobulin (IVIG) with a median number of days from fever onset to IVIG administration of 7.2. A second dose was given to 15.7% and steroids to 14.5% patients. Only 1.4% patients received infliximab. No deaths were reported. A multivariate analysis identified anemia, hypoalbuminemia, hyponatremia, higher creatinine and procalcitonin as independent risk factors for treatment failure and length under 103 cm, hemoglobin < 10.2 mg/dL, platelets > 900,000 cells/mm³, maximum temperature < 39.5°C, total duration of fever > 10 days and fever before treatment ≥ 8 days as independent risk factors for developing coronary aneurysms. In our population, children under 12 months develop coronary aneurysms more frequently and children with KD with anemia and leukocytosis have high risk of cardiac involvement. Adding steroids early should be considered in those patients, especially if the treatment is not started before 8 days of fever. A score applicable to non-Japanese children able to predict the risk of aneurysm development and IVIG resistance is necessary.

Kawasaki disease (KD) is a multisystem vasculitis of small and medium vessels typical of childhood. Timely treatment with intravenous immunoglobulin (IVIG) has reduced the incidence of coronary artery abnormalities (CAAs) from 25% to approximately 4%.1 Asian studies have focused on infants under 3 months of age, but there are no published data about these patients from Western countries.2 3 We reviewed 621 patients under 16 years old with a diagnosis of KD between 2011 and 2016 from a multicentre study in Spain (KAWA-RACE study); 84 hospitals participated throughout the country. We found seven children under 90 days (1.13%), with a male predominance (6 of 7). Five presented irritability, but only two fulfilled the criteria for complete KD (table 1).1 The following were the main laboratory findings (median, IQR): highest C reactive protein (CRP) 24 mg/L (8.48–31.4), highest erythrocyte sedimentation rate 79 mm (70–105.5), maximum and minimum platelet count 900 ×10^9/L (682–1 117) and 506 ×10^9/L (449–612), minimum haemoglobin 10 g/dL (9–10.8), maximum leucocytes 21 ×10^9/L (16.45–23.37), minimum sodium 135.5 mEq/L (133–137.5), and minimum albumin 2.9 mg/dL (2.6–3.4). View this table: Table 1 Diagnosis, symptoms, cardiological and microbiological findings In three cases, a viral infection was diagnosed and four patients presented with CAA, but no other echocardiographic findings were detected (table 1). The median time interval since fever onset to IVIG administration was 8 days. All patients responded well to the first dose of IVIG, and only one received concomitant intravenous steroids because he was considered to be at high risk for IVIG resistance. All CAAs were transient and resolved during follow-up (table 1). Epidemiology is different in Western countries when compared with Asian …