An Unusual Case of “Conjugal” Polymyalgia Rheumatica after SARS-CoV-2 Vaccination

The rare occurrence of polymyalgia rheumatica (PMR) in married couples has been reported in the literature. Susceptibility to PMR is contributed by genetic and environmental factors and cases of PMR developing after influenza vaccine have also been described, in a debated phenomenon known as ‘ASIA’ syndrome. We report the case of two cohabitating married patients developing PMR few weeks after the first dose of ChAdOx1-S SARS-CoV-2 vaccine. Both patients presented with typical symptoms suggestive of PMR. Laboratory findings and ultrasound examination confirmed the diagnosis. Glucocorticoid therapy led to rapid improvment of symptoms. Anti-receptor-binding domain IgG titre was tested and, eight weeks after vaccination, both patients showed no antibody response. It has been suggested that vaccines might trigger autoimmune or inflammatory states in predisposed individuals and various hypotheses have been made regarding the pathogenesis of PMR. Although the causative effect of vaccines cannot be determined, the close temporal correlation observed in our case supports the potential role of environmental factors in triggering the onset of PMR. However, the literature indicates that post-COVID19 vaccination immune-mediated or inflammatory adverse events are extremely rare and vaccination should be encouraged since the benefit largely outweighs possible risks.