Influence of weather conditions on rheumatic pain.

Objective: To evaluate the influence of the weather in Cordoba City, Argentina, on pain in patients with rheumatic pain; to correlate different climate variables with the patients' impression of weather sensitivity; and to assess correlations between pain and climate conditions on 5 days preceding and following painful episode.

Methods: Self-reported questionnaires to assess the presence and features of spontaneous daily pain during one year (1998) were completed by 151 outpatients with osteoarthritis (OA) (n = 52), rheumatoid arthritis (RA) (n = 82), and fibromyalgia (FM) (n = 17) and 32 healthy subjects. Data were correlated with daily temperature, atmospheric pressure, and relative humidity obtained during the same period. Only p values < 0.001 were considered significant.

Results: Low temperature, high atmospheric pressure, and high humidity were significantly correlated with pain in RA (r = -0.30, r = 0.34, r = 0.23, respectively; p < 0.001); in OA, pain correlated with low temperature and high humidity (r = -0.23, r = 0.24; p < 0.001); in FM, with low temperature and high atmospheric pressure (r = -0.255, r = 0.22; p < 0.001) and no correlation was found in controls. Patients self-described as being weather sensitive correlated only with high humidity (r = 0.45; p < 0.001). There was no better correlation with climate variables, except for humidity, 5 days before or after the day of the painful episode.

Conclusion: These results support the belief that weather influences rheumatic pain, albeit in different ways depending on the subjacent pathology and subjective weather sensitivity. This influence may not depend on weather conditions of the previous or following days, indicating that climate would not be a pain predictor and vice versa.