s >10,000 with myalgia and weakness are now reported in more than 10% of COVID-19–infected patients.6 Although COVID-19–associated myopathy has not yet been studied but only characterized as skeletal muscle injury or rhabdomyolysis,6 2 just published cases suggest an autoimmune COVID-19–triggered NAM. One, an 88-year-old man from New York presented with acute bilateral thigh weakness and inability to get up from the toilet, without fever or other systemic symptoms, and very high CK level (13,581 U/L).20 He was found COVID-19 positive and given hydroxychloroquine, and a week later, his painful weakness improved with CK reduction. The other, a 60-year-old man from Wuhan had a 6-day history of fever, cough, and COVID-19–positive pneumonia with normal strength and CK; 7 days later, although systemically had improved, his CRP doubled and developed painful muscle weakness with very high CK (11,842 U/L).21 He was given IVIg and his strength improved while became COVID-19 negative.
Myopathic symptoms in a severe systemic viral disease are multifactorial, but an acute onse