No abstract

Benign acute childhood myositis (BACM) is a self-limited childhood illness, and viral infections mainly cause it. Clinical and laboratory alterations usually normalize rapidly; generally, the only medical intervention required is supportive (hydration and analgesic medication). The low awareness about BACM often led to delayed diagnosis and unneeded ancillary investigations. This study aims to better characterize the clinical and laboratory features of BACM to improve the diagnostic process and inpatient and outpatient management. We conducted a retrospective study selecting all children admitted to Meyer’s Children’s Hospital-IRCCS (Florence, Italy) with a diagnosis of BACM over the last 5 years, both those visited at Emergency Department (ED) and those admitted to the Pediatric Unit. Clinical, laboratory, and instrumental data were collected from electronic clinical records and analyzed. Overall, sixty-five patients were enrolled; 49 children were visited and discharged directly from ED, whereas 16 were admitted in the Pediatric or Neurologic Wards. The median age was 6.56 years (IQR 4.9–9.1). Male gender (66.1%) and Caucasian ethnicity (70%) were prevalent. Most patients were admitted during winter, and a second peak was found in autumn. All patients had bilateral calf pain, most of them (87.7%) associated with asthenia and refuse to walk (93.8%). Prodromal symptoms were fever (75.3%), cough (32.3%), coryza (26.1%), sore throat (26.1%), and vomiting (15.3%). The median value of CPK was 1827 U/L (IQR 915.5–2462) at peak. CPK median time to normalization was 7 days (IQR 7–8.5) from the nadir. Influenza B was the virus most frequently BACM associated, followed by Influenza A; a novel association with Sars-CoV-2 has been detected. Two patients had pathogenic variants at the Next Generation Sequencing myopathies panel.    Conclusion: School-aged children admitted to the hospital with walking difficulty and myalgia, generally after an upper respiratory tract infection with a moderate CPK elevation, should remind at first of BACM. Rapid complaint resolution and biochemical markers normalization will prevent unnecessary tests and inappropriate therapies. What is Known:• BACM is a self-limited syndrome associated with acute infections. Influenza A and B viruses are the main etiological agents, but BACM may be related to many other microorganisms like Parainfluenza virus, Epstein-Barr virus, Cytomegalovirus, Human herpesvirus 6, Respiratory syncytial virus, Coxsackieviruses, Mycoplasma pneumoniae, Streptococcus pyogenes, Legionella, and Salmonella spp.• Clinical and laboratory alterations usually normalize rapidly; generally, the only medical intervention required is supportive (hydration, analgesic medication). Evolution in rhabdomyolysis and kidney damage is possible but rarely reported. What is New:• Sars-CoV-2 could be an emerging possible cause of BACM. During and after the Sars-CoV-2 outbreak, virus infection seasonality has changed, and so has BACM seasonality.• Screening tests for muscular and metabolic disorders are recommended in recurrent myositis and/or cases with marked CPK elevation (≥ 5000 U/L).

Purpose: Benign acute childhood myositis (BACM) is a self-limited childhood illness, and it is mainly caused by viral infections. Clinical and laboratory alterations usually normalize rapidly; generally, the only medical intervention required is supportive (hydration, analgesic medication). The low awareness about BACM often led to delayed diagnosis and unneeded ancillary investigations. This study aims to better characterize the clinical and laboratory features of BACM to improve the diagnostic process and inpatient and outpatient management. Materials and methods: We conducted a retrospective study selecting all children admitted to Meyer's Children's Hospital-IRCCS (Florence, Italy) with a diagnosis of BACM over the last 5 years. Clinical, laboratory, and instrumental data were collected from electronic clinical records and analyzed. Results: Sixteen patients were enrolled. The median age was 7.68 years (IQR 5.7-12.9). Male gender (62.5%) and Caucasian ethnicity (68.75%) were prevalent. Most of the patients were admitted during winter, and a second peak has been found in summer. All patients had bilateral calf pain at admission (87.5%), associated with asthenia, and refuse to walk (93.7%). Prodromal symptoms were fever (81.25%), cough (37.5%), coryza (43.5%), sore throat (50%), and vomiting (31.25%). The median value of CPK was 2,183.5 U/L (IQR 1,395.5-7,156.25) at peak. CPK median time to normalization was 7 days (IQR 7-8.5) from the nadir. Influenza B was the virus most frequently BACM associated, followed by influenza A; a novel association with Sars-CoV-2 has been detected. Two patients had pathogenic variants at the Next Generation Sequencing myopathies panel. Conclusions: School-aged children admitted to the hospital with walking difficulty and myalgia generally after an upper respiratory tract infection with a moderate CPK elevation should remind at first of BACM. Rapid complaint resolution and biochemical markers normalization will prevent unnecessary tests and inappropriate therapies.

Background: Lung ultrasound (US) proved useful in patients with COVID-19, but limited data are available about its use in affected children. Aim: Lung ultrasound (US) is in the front door in the assessment of patients with coronavirus disease 19 (COVID-19), but limited data are available about its use in affected children. We aimed to describe lung US features and discuss its potential applications in COVID-19 children considering the usually mild disease course. Methods: We performed lung US to children with COVID-19 admitted between March 1st and April 27th, 2020. Clinical and radiological data were collected. One or more subsequent lung US were obtained from all subjects. Results: A series of 13 confirmed COVID-19 children were recruited. 8/13 patients showed signs of respiratory interstitial syndrome as for focal or coalescent B-lines or white lung, also in the absence of relevant clinical symptoms. Conclusions: As clinical characteristics of pediatric COVID-19 differ from adults, it is of interest to determine whether pediatric lung US shares the same imaging pattern of adults and whether COVID-19 pneumonia may differ from other virus pneumonia. Our small series highlighted that lung US documented signs of interstitial pneumonia in paucisymptomatic or asymptomatic pediatric patients. In conclusion, we pinpoint the usefulness of point of care lung US for the evaluation of infected children correlated with clinical information.