In January 2019 researchers from Japan published the results of their study to assess whether the seasons influenced rheumatoid arthritis activity. A total of 12,839 individuals were investigated, and involved 3250 individuals from the spring period, 916 the summer, 1021 the autumn and 7652 the winter. Disease activity was assessed as remission, low, moderate or high, with the affected joint distribution also being assessed. Results showed that disease activity appeared to be highest in the spring and moderate in the winter. Autumn, on the other hand, appeared to be associated with a higher remission rate. There were also significant seasonal differences with respect to affected joints in the upper and lower extremities but no seasonal difference for large joint predominance. The researchers concluded that healthcare providers should be aware of seasonal fluctuations in the symptoms of rheumatoid arthritis, particularly the deterioration that can occur in winter and spring, and to help individuals adjust to seasonal changes in terms of their daily living activities (eg by temporarily increasing their doses of pain medication if necessary).
Mori H et al. Influence of seasonal changes on disease activity and distribution of affected joints in rhaumatoid arthritis. BMC Musculoskelet Disord. 2019 Jan 18;20(1):30