COVID-19 vaccine-associated myositis
A 53-year-old healthy man received the first dose of the ChAdOx1 nCoV-19 vaccine (COVISHIELD) into his left deltoid muscle. He experienced pain in the left upper arm, followed by the right upper arm and bilateral calf muscles (left more than right). The pain gradually increased, restricting his daily activities. On the 11th day of vaccination, he had difficulty walking and moving his left arm. He also reported generalized muscle weakness, more pronounced in the proximal upper and lower limbs than the distal ones. His medical history was unremarkable with no evidence of COVID-19 infection in the past. Serologic testing yielded mildly increased serum creatine kinase (187 U/L, reference range 40–171 U/L) and alanine transaminase (50 U/L, reference range 10–40 U/L) concentrations. Serum bilirubin, aspartate aminotransferase (AST), gamma glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and C-reactive protein levels were normal. Urine analysis excluded myoglobinuria. On M...