Role of aeroallergen nasal challenge in asthmatic children.

ABSTRACT

BACKGROUND: The majority of allergic asthmatic patients are sensitised to several aeroallergens. Discrimination of the clinically relevant allergen is essential for the correct use of immunotherapy. OBJECTIVE: To investigate nasal challenge and its role in screening clinically relevant allergens in asthmatic children. METHODS: Aeroallergen nasal challenge was performed in five different groups of patients (asthma; asthma & rhinitis; rhinitis; atopic controls; and non-atopic controls). Differences between groups after challenge were evaluated by means of spirometry and acoustic rhinometry. RESULTS: Nasal challenge was performed in 125 patients, 25 per group. The positive nasal response of immediate type was recorded in 21 patients with asthma only (P<0.001), 18 with asthma and rhinitis (P<0.001), 19 with rhinitis (P<0.001), two atopic control patients and in no healthy control patients. However, no differences were observed between the asthma group and the groups with rhinitis symptoms. The risk of a positive challenge was much higher in the asthma without rhinitis group compared to atopic controls (OR 29.57; 95%CI 5.47-159.97). CONCLUSION: Aeroallergen nasal challenge is a safe technique in asthmatic children and could be useful in establishing the clinically relevant allergen even in the absence of rhinitis.