Inflammatory
Myopathy

	Muscle Weakness	Abnormal Gait or Difficulty Walking	Elevated Creatine Kinase	Respiratory Insufficiency	Difficulty Swallowing	Exercise Intolerance
Inflammatory Myopathy 14 to 25 per 100,000
Pompe disease 2.5 per 100,000

Overview

• Inflammatory myopathy is a general term encompassing a group of acquired diseases that occur when an autoimmune reaction occurs in the body, causing it to attack the muscles
  • Inflammatory myopathies include polymyositis and dermatomyositis
• Signs and symptoms of certain inflammatory myopathies can be similar to those of Pompe disease

Signs and Symptoms

• Inflammatory myopathy results in a weakness and loss of muscle strength most commonly in large muscles around the neck, shoulders, and hips
• Similar to Pompe disease, signs of muscle weakness can include difficulty getting up from a seated position or climbing stairs, or with lifting objects above your head
• Skin rashes such as red or purple spots on the eyelids or red, scaly bumps on the knees, elbows or knuckles can be seen with certain inflammatory myopathies, but is not typically seen in Pompe disease

Diagnosis

• Genetic testing is currently available for many genetic disorders, including some inflammatory myopathies that have signs and symptoms that overlap with Pompe disease
• Similar to Pompe disease, tools including laboratory tests (e.g., creatine kinase), electromyography (used to study the electrical activity of muscles) and muscle biopsy may be used

The information presented is intended as a brief overview. It is not an exhaustive summary of inflammatory myopathy. For more information on inflammatory myopathy, visit: https://www.ninds.nih.gov/Disorders/All-Disorders/Inflammatory-Myopathies-Information-Page

For more information on the diagnosis of Pompe disease, visit Diagnostic Journey: Infantile-Onset Pompe Disease and Diagnostic Journey: Late-Onset Pompe Disease