Prevalence of allergy
| Non-RA patients (n=339) | RA patients (n=304) | ||||||
|---|---|---|---|---|---|---|---|
| n=(%) | Mean age | (range) | n=(%) | Mean age | (range) | ||
| No allergy | 237 (70) | 53.1 | (17–91) | 244 (80) | 58.5 | (21–91) | |
| Alleged allergy | 102 (30) | 46.5 | (20–83) | 60 (20) | 53.8 | (24–82) | |
| alleged hay fever | 38 (11) | 44.5 | (22–68) | 13 ( 4) | 46.0 | (24–77) | |
| Confirmed hay fever | 28 (8) | 44.1 | (22–68) | 12 ( 4) | 48.4 | (24–77) | |
Prevalence of allergy derived from a questionnaire administered to 643 consecutive patients of our rheumatology outpatient clinic. RA was diagnosed according to the 1987 revised ACR criteria. Hay fever was confirmed by a positive reaction to intracutaneously injected inhalation allergens or the presence of specific IgE antibodies, or both. The prevalence of hay fever was significantly lower among RA patients (4%) compared with non-RA patients (8%).The average age of the RA group did not differ from that of the non-RA group, nor was the average age of the hay fever patients in the RA group different from that of the non-RA group. A relative risk for hay fever in the RA group compared with the non-RA group of 0.48 (95% confidence intervals: 0.25, 0.92, p<0.05) was calculated.