The study objective: to analyze the IgE mediated sensitisation to common inhalant allergens in adult patients suffering from severe difficult-to-control asthma according to GINA guidelines.
Methods: 123 patients (57 women and 56 men, mean age 52.7±10.1 years) were included into the study. The detailed personal and family history was assessed by the use of a original questionnaire. Skin prick tests (Allergopharma, Germany) and specific IgE serum level against common inhalant allergens (Poly–Check, Immunogenetics, US) and spirometry were performed.
Results: 79 (64%) patients had a positive family history of asthma. Mean time of asthma duration was in average 20.8 ± 15.1 years. Late onset of asthma (above 50 year of age) was observed in 61 (50%) subjects. 17 (14%) patients were current and 29 (24%) former smokers. Atopy estimated on the basis of the presence of at least one positive skin prick test was observed in 81 (68%) patients, mostly in men. Mean total serum IgE level was 80.2 ±17 IU/l (range: 2.7- 1205.4).
House dust mites allergy was predominant and confirmed in 49 (40%) patients with mean specific IgE against D.pteronissinus 17.4 ± 10.2 IU/l and against D. farinae 18.2 ± 9.2 IU/l. Alternaria and cat allergy were diagnosed in 20 (16.4%) and 29 (23.6.3%) subjects respectively. The prevalence of inhalant sensitization was more frequently observed in those with asthma and other allergic disease than in patients with asthma alone (table 1). It was statistically significant in chi-quarter test for p<0.01
Conclusion.
Positive family history of asthma, late onset of disease as well as IgE sensitivity to inhalant allergens are the common features of severe, difficult-to-control asthma. However, inhalant sensitivity occurs predominantly in cases of asthma concomitant with other allergic diseases.