Aim: To investigate the association of benign acute childhood myositis (BACM) with respiratory viruses. Also, we aimed to assess the effect of antiviral treatment on the improvement and complications.
Methods: This study was conducted at an urban-academic emergency department during four influenza-seasons (2016-2019), retrospectively. Demographics, clinical findings, laboratories, metabolic disease analyses and serological features were extracted from the medical records. Treatments, complications and outcomes were also recorded.
Results: A total of 114 children were included. The median age was 7.0 (min 1.25-max 17) years and 78.9% were male. The most common symptoms were leg pain (91.2%), anorexia (54.4%), fever (45.6%), sore throat (42.1%) and walking difficulty (32.5%). On admission, the median creatine phosphokinase level was 3332 IU/L (range, 1634-50 185), median aspartate aminotransferase 107 U/L (range, 38-1798). In the multiplex polymerase chain reaction analysis, 40.4% influenza B, 36.8% influenza A, 7.8% adenovirus, 7.8% parainfluenza virus, 5.3% rhinovirus, 5.3% respiratory syncytial virus and 1.8% Mycoplasma pneumoniae were detected. Rhabdomyolysis was developed in 6.7% and acute renal failure was seen in two patients. Oseltamivir was given in 44 (38.6%) patients who had influenza A/B. Metabolic disease screening tests were performed in 33.3% of patients and metabolic diseases were detected in 4 (3.5%) patients. The median recovery time was lower in patients with oseltamivir treatment (4 (min 2-max 5) - 5 (min 3-max 10) days) (P < 0.001).
Conclusion: Rhabdomyolysis is more common in BACM due to the influenza A virus. The early use of oseltamivir treatment was significantly associated with a shorter recovery time.
Keywords: BACM; children; influenza; myositis; oseltamivir.
© 2022 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).