ABSTRACT
Introduction: Influenza-related viral myositis is observed mostly in children with influenza, and the disease is more common in influenza type B. The aim of the present study was to evaluate the prevalence, and clinical and laboratory features of acute viral myositis in children with influenza in 2019 and 2020. Methods: This retrospective cross-sectional study was performed in Ali Asghar Hospital, from December 2019 to February 2020. Children aged 2-14 years with symptoms of acute onset of fever, along with the symptoms of influenza with or without muscle pain who referred to the emergency department of Hazrat Ali Asghar Children's Hospital, were included in the study. The data were collected and analyzed by Statistical Package for the Social Sciences (SPSS) version 22. Results: Out of the 105 participants in this study, 62 (59%) were male and the rest were female. The average age of the patients was 5.34 years (SD = 2.63). Clinical signs of lower limb pain, myalgia, lameness, weakness, and lethargy were significantly more common in patients with myositis (P-value < 0.05). In-vitro examination demonstrated that creatine phosphokinase (CPK), aspartate aminotransferase (AST), and aAlanine aminotransferease (ALT) levels were significantly higher in patients with myositis. Conclusion: Based on the present results, the clinical symptoms in patients are quite clear, and based on the symptoms, it is possible to diagnose and treat myositis without relying on laboratory findings; due to the self-limitation of this complication and lack of the need for complex treatments in case of early diagnosis, physicians can diagnose and treat many cases, depending on the clinical symptoms and the accuracy of the examination.