In order to evaluate comorbidity of type I allergic disorders in patients with Rheumatoid Arthritis (RA), we studied their morbidity of allergic disease and prevalence of sensitivity to some of the important inhaled allergens in Japan.
In 99 outpatients with RA, males 20/females 79, average age 65±13 Y-O, we checked their allergic history and symptoms by questionnaire and examined their serum IgE levels, which were HD-Mite (HDM), Japanese Cedar (JC), Orchard Grass (OG). All of them consented to our study. Moreover, from June to October in 2013 our hospital used 179 middle aged employees without RA as a control group, males 51/females 128 and average 48±8 Y-O, studying the same data as the RA patients.
Allergic history and/or symptoms of RA patients were Allergic Rhinitis and/or Pollinosis (AR/P) 30.3%, Bronchial Asthma 8.1%, Atopic dermatitis 2% and Urticaria 11.1%. Those of the control group were, respectively, 31.3%, 3.9%, 3.4% and 4.4%. In RA patients the percentage of AR/P was almost the same as the control group. On the other hand positive sensitivity (over class 2) to the inhaled allergens in RA patients was HDM 15.2%, JC 27.3% and OG 11.1%. In the Control group it was, respectively, 40.2%, 50.5% and 13.4%. The sensitivity rate of HDM and JC was significantly lower (p<0.001) in RA patients than in the control group.
RA patients had a lower sensitivity to HDM and JC antigens than the control group but had the same positive allergic history/symptoms as the control group.