Why is polymyalgia rheumatica a disease of older adults? Explanations through etiology and pathogenesis: a narrative review.

Polymyalgia rheumatica is one of the most common inflammatory rheumatic conditions in older adults. The disease is characterized by pain and stiffness in the shoulder and pelvic girdle. Polymyalgia rheumatica is almost always observed in adults over the age of 50. The current article aimed to provide explanations for the age preference of polymyalgia rheumatica by reviewing the literature regarding disease etiology and pathogenesis. Potential factors related to the association between polymyalgia rheumatica and aging include immunosenescence/inflammaging, increased risk of infections by aging, endocrinosenescence, and age-related changes in gut microbiota. These factors and their potential contributions to immune-mediated inflammation will be discussed.