Parsonage-Turner syndrome as a side effect of booster vaccination
A 50-year-old man visited a primary care clinic with persistent right arm pain and weakness lasting for 9 weeks. These symptoms began 5 days after receiving a mRNA COVID-19 booster vaccination in his right deltoid. The patient experienced a moderate-to-severe ache at the injection site, radiating to his neck. Over time, he developed progressive weakness in his right shoulder and elbow, along with occasional hand paresthesia. Despite reporting his symptoms to Malaysian equivalent of VAERS database, the patient sought medical attention only after 9 weeks when his symptoms worsened to the point where he needed assistance with daily activities. He had no other symptoms or relevant medical history, except for completing two doses of an inactivated COVID-19 vaccine 7 months prior. Physical examination revealed muscle wasting in the affected areas without skin changes or tenderness. Neurological evaluations, including nerve conduction studies and electromyography, indicated axonal loss rathe