Polymyalgia Rheumatica Following Respiratory Syncytial Virus (RSV) Vaccination.

Introduction: Polymyalgia rheumatica (PMR) is a chronic inflammatory disorder that causes stiffness and pain in the proximal joints, including the shoulders, hips and neck. The exact cause of polymyalgia rheumatica is yet to be fully understood, but research suggests that both genetic and environmental factors may contribute to it. Studies have previously linked the onset and relapse of polymyalgia rheumatica symptoms to the influenza and COVID-19 vaccines. The Food and Drug Administration approved the respiratory syncytial virus (RSV) vaccine, which is a recombinant protein vaccine for adults over 60, in May 2023. No previous reports of polymyalgia rheumatica onset or relapse have been linked to the RSV vaccine. The human proteome shares some peptides with the RSV F antigen, suggesting a high risk of cross-reactivity when using that antigen in vaccination formulations.

Case description: A 72-year-old man experienced a new onset of bilateral shoulder pain and stiffness three days after receiving the Abrysvo^® RSV vaccine. The symptoms lasted more than an hour (up until noon) and interfered with his activities of daily living. Inflammatory markers such as C-reactive protein were elevated. The patient's symptoms and inflammatory marker levels significantly improved with prednisone therapy.

Conclusion: In patients with typical PMR symptoms, it is important for clinicians to carefully review immunisation history to rule out any potentially related adverse effects.

Learning points: Vaccines can trigger autoimmune diseases in some individuals.This case report suggests respiratory syncytial virus (RSV) vaccine is among the possible triggers for polymyalgia rheumatica.