235 Frequency of Patients With Clinical Manifestations of Allergic Rhinitis without Evidence of Systemic Atopy and Specific ige Sensitization

BACKGROUND: The diagnosis of allergic rhinitis (AR) is based on clinical manifestations and supported by a positive result for skin prick test (SPT) or serum specific immunoglobulin E (sIgE) antibodies to aeroallergens. Our objective was to investigate the frequency of patients with clinical manifestations of AR without evidence of specific IgE sensitization. METHODS: We evaluated patients with clinical manifestations suggestive of AR, other causes of rhinitis excluded, aged >5 years and who had total serum IgE and SPT or sIgE to aeroallergens measured. Skin tests were performed with extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis and Aspergillus fumigatus (FDA Allergenic) and total serum IgE and sIgE, for the same allergens, by ImmunoCAP (Phadia). Patients were subdivided into groups according to the results profile, and comparatively analyzed for association with asthma, severity of rhinitis and age. RESULTS: We evaluated 116 patients (64% female) aged between 5 and 79 years, including 34 children (29%) and 63 (54%) with bronchial asthma. The observed profiles and frequencies were: high IgE levels and positivity in the SPT or sIgE –55%; normal IgE levels and SPT or sIgE positivity –9%; high IgE levels and SPT and sIgE negativity –3 %; normal IgE levels and negativity in the SPT and sIgE –23%. Among patients with normal levels of total serum IgE and no evidence of specific IgE sensitization, 14% had asthma, while in the remainder the prevalence of asthma was 34% (P = 0.0009). There was no statistical significance in the influence of the rhinitis severity and age in the absence of markers of atopy and allergen sensitization. CONCLUSIONS: We observed a significant number of patients with clinical manifestations of AR, without evidence of systemic atopy and specific IgE sensitization, indicating the importance of careful research of local allergic rhinitis, as well as other causes of chronic rhinitis. Local allergic rhinitis appears to be less frequent in patients with rhinitis and asthma. The observation of 13% of patients with elevated levels of total IgE without specific sensitization implies the possibility of sensitization to aeroallergens which were not investigated, such as occupational allergens.