Acute benign myositis of childhood: Results of a prospective study performed in a pediatric emergency department

OBJECTIVE: Benign acute childhood myositis is characterized by acute musculoskeletal involvement leading to transient limitations on deambulation followed by a viral illness. Our study objective to evaluate clinical and laboratory features of patients in a pediatric emergency department. METHODOS: We conducted a prospective study in patients with symptoms and laboratory findings compatible with viral myositis in the period of August 2017 to August 2018. RESULTS: We assessed 20 patients in the period of twelve months. The mean age was 8,25 years. Of these, 83,3% had infectious symptoms in the week before the musculoskeletal involvement. By the time of the diagnosis, the symptoms were: calf pain, reluctance to walk, gait abnormality, diffuse myalgia and calf weakness. The most relevant laboratory finding was the elevation of CPK (mean 3359,556U/L) level, followed by AST (mean 131U/L) and ALT (mean 64,66U/L) elevation. The mean time for symptom relief was 3 days and in 7 days all exams were normal. CONCLUSION: Though the exact incidence of this condition remains undetermined, the lower extremity pain and the gait abnormality is of concern of both parents and health care providers. We emphasize the importance of knowing this condition to avoid unnecessary exams and the delay in the diagnosis of severe conditions.