# Benign Acute Childhood Myositis: A Three-Year Experience From a Pediatric Department in Poland

## TL;DR

This study reviews cases of a muscle condition in children that causes sudden leg pain and walking issues, often after a viral infection.

## Contribution

The study contributes a three-year clinical analysis of BACM cases from a Polish pediatric department.

## Key findings

- BACM typically follows a viral illness and presents with elevated muscle enzymes like CK and AST.
- The condition is self-limiting and requires only supportive care.
- Distinguishing BACM from rhabdomyolysis is clinically important due to differing severity.

## Abstract

Benign acute childhood myositis (BACM) is a condition characterized by the sudden onset of bilateral lower limb muscle pain and gait disturbances, usually appearing a few days after a viral flu-like illness. Although most often linked to influenza virus infection, various other pathogens have also been reported. The disease mainly affects children during late autumn, winter, and early spring. Laboratory findings often show temporary elevation of muscle enzymes, particularly creatine kinase (CK) and aspartate aminotransferase (AST). Despite its striking presentation, BACM is self-limiting with an excellent prognosis and typically requires only supportive care, including rest, hydration, and analgesia. A key clinical challenge is distinguishing BACM from rhabdomyolysis, a more serious condition involving extensive muscle breakdown, which can lead to worsening general condition, altered consciousness, and acute kidney injury. This retrospective study analyzes the clinical and laboratory features of children diagnosed with BACM and hospitalized between April 2022 and April 2025 in the Clinical Department of Pediatrics in Bytom, Poland. To identify similarities and differences, the findings were compared with data from other studies in international medical databases. Overall, the study conclusions were consistent with previously published literature.