Outcome of Benign Acute Childhood Myositis: The Experience of 2 Large Tertiary Care Pediatric Hospitals.

OBJECTIVE: The aims of the study were to determine the evolution of benign acute childhood myositis in children and to assess the relationship between creatine phosphokinase (CPK) values and myoglobinuria.

STUDY DESIGN: A retrospective study of patients with benign acute childhood myositis seen in 2 tertiary care university-affiliated pediatric hospitals during overlapping 4-year periods.

METHODS: Demographic data, historical details, clinical, and laboratory results were extracted from the charts of children younger than 16 years with a CPK greater than 3 times normal. Complications, treatments, and outcomes were recorded.

RESULTS: Fifty-four children were included, 43 (80%) were male, and mean age was 7.3 years (median [range], 6 [3-16] years), none showed abnormal neurological findings, manifested hematuria, or developed renal failure. Mean CPK level at presentation was 1872 IU/L (range, 511-8086 IU/L). None developed renal failure, and there were no adverse outcomes on follow-up.

CONCLUSIONS: Acute childhood myositis is a predominantly benign disease. Neurological examination is usually normal and rhabdomyolysis is rare. Although severe pathological comorbid conditions must be excluded, a complete history and examination, coupled with simple blood and urine tests, can help minimize unnecessary diagnostic investigations.