Benign acute childhood myositis: our experience on clinical evaluation

Background: Benign Acute Childhood Myositis (BACM) is a transient condition mainly affecting children of school-age characterized by muscle pain, typically localized to the calf muscle with symmetrical lower extremity pain and difficulty in walking. Usually the clinical picture is preceded by a viral infection including influenza, parainfluenza, rotavirus and mycoplasma. Methods: The case-series was conducted in 4 pediatric hospitals in Catania, Italy, over a 12-year observational period. Clinical examination, laboratory data, course, treatment, and complications of the affected children were extracted from electronic medical records of each hospital. Results: For the case-series, fifty children diagnosed with BACM were enrolled: the mean age of affected children was 5.35 years, 86% of were males and in 56% the affections occurred during the winter. In the affected children, the clinical picture was characterized by previous fever and/or symptoms of inflammation of the upper airways, and followed by pain in the lower extremities up to uncoordinated gait. In 17 cases the etiological agent was isolated. In all the children the muscular symptomatology had a good evolution with progressive marked reduction of pain and of the high level of CKemia. Neither clinical recurrences nor sequelae were reported. Conclusions: BACM shows to have in most of the cases a favorable evolution, a spontaneous remission of symptoms and a good prognosis. It is worthy a rapid and early diagnosis in order to avoid unnecessary diagnostic investigations and a careful follow up necessary to exclude persistence of symptoms or CK elevation.