This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal  disorders, Subject name: Pediatrics
Perifascicular Atrophy is seen in 
Select and explain. 
A. Duchenne Muscular Atrophy, B. Wilson disease, C. Beckers's dystrophy, D. Dermatomyositis
D: Dermatomyositis
Answer: D: Dermatomyositis 
Explanation: .It acts mostly like an autoimmune disorder. That means your body mistakes its own tissues as the enemy and attacks itself. When you have dermatomyositis, yourimmune system goes after the blood vessels inside your muscles and the connective tissues in your skin. The pathology of dermatomyositisincludes inflammation, vasculitis, and perifascicular atrophy. ... A distinctive feature ofdermatomyositis is atrophy and degeneration of myofibers at the periphery of fascicles (perifascicular atrophy-PFA), which occurs even in absence of inflammation