Polymyalgia Rheumatica After ChAdOx1 nCov-19 Vaccine: A Case Report.

Polymyalgia rheumatica (PMR) is an inflammatory rheumatic disease characterized by severe pain and morning stiffness, mainly affecting the shoulder girdle. A 75-year-old woman, previously healthy, received the first dose of ChAdOx1 vaccine and two weeks later started with pain in the shoulder and pelvic girdles and knees of inflammatory characteristics, accompanied by morning stiffness (about one hour), anorexia, asthenia, and activities of daily living (ADL) dependence. She started analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) with no improvement. The symptoms aggravated three days after the second vaccine dose, and she was referred to our center. At observation, she presented shoulder, hip, and knee active range of motion limitation. Blood analysis revealed an Erythrocyte Sedimentation Rate (ESR) of 120mm/h (reference value < 20mm/h) and C-Reactive Protein (CRP) of 80mg/L (reference value < 5mg/L). Ultrasound showed effusion on both shoulders, hips, and knees. The paraneoplastic syndrome was ruled out. She started oral corticosteroids and a rehabilitation program, and a month later, she presented controlled pain, normal analysis, and ADL independence. This case shows symptomatic and analytic features of PRM after the first vaccine dose and aggravation soon after the second. As such, we consider establishing a potential relationship between the inoculation and the development of PRM. A few cases were published reporting a PRM-like syndrome following a COVID-19 vaccine; however, the underlying mechanism and prognosis are still unknown.