A negative association has been observed between Th1 and Th2 mediated diseases. The purpose of this study was to verify the frequency of atopy in patients with DM1.

The ISAAC written questionnaire was applied for in 90 outpatients with DM1 in order to establish the prevalence of asthma and rhinoconjunctivitis symptoms, and compare with those obtained from previous survey. Serum total IgE and specific IgE antibodies to D. pteronyssinus were determined by Pharmacia Immunocap®. A panel of six common aeroallergens was used for skin prick tests (SPT) in volar forearm surface. A positive SPT was considered if wheal cross diameters were ≥2mm.

Ages ranged from 3 to 19 years (median 11.7) and 47 (52%) were male. The prevalence of wheezing in the past 12 months was 12.2%; 26.7% referred nose and eye symptoms in the past 12 months. In 2001 the frequency of these symptoms in 13-14 year-old schoolchildren of Curitiba was respectively 18.7% and 17%. A positive skin test and specific IgE levels ≥0.7 kU/L were observed in 29.5% and 31.3% respectively, with a significant association between them (p<0.001). Upper and lower respiratory symptoms were also associated with a positive SPT (p<0.05).

Atopy does coexist with DM1 suggesting that Th1 and Th2 phenomenon are independent in those conditions. The frequency of rhinitis was higher than the frequency of asthma in DM1.