Metabolic vs inflammatory myopathy: Diagnostic difficulties and errors in myopathies – case report

Glycogen storage diseases are genetic metabolic disorders of glycogen metabolism. There are more than 12 types and they are grouped based on the enzyme deficiency and the affected tissue. We present the case of a 43-year-old female with glycogen storage disease type III with liver, skeletal and cardiac muscle involvement whose disease was misdiagnosed with idiopathic inflammatory myopathy and treated with glucocorticoids. Glucocorticoids are an inadequate therapy for this metabolic myopathy and they interfere with the carbohydrate metabolism causing more glycogen storage in the liver.