The proportion of local allergic rhinitis to Dermatophagoides pteronyssinus in children

Background: Local allergic rhinitis (LAR) is diagnosed by the positive response to nasal allergen provocation test (NAPT) to aeroallergen and/or local synthesis of specific IgE (sIgE). This entity is found in half of the adults with non-allergic rhinitis (NAR). In children, very few data of the prevalence and characteristics of LAR were reported. Methods: Children 8–18 years with NAR were recruited. A NAPT with Dermatophagoides pteronyssinus extract (NAPT-Dp) at 200, 600, and 2000 AU/ml, respectively, at 15-min interval was performed. The immediate response was assessed using the clinical symptom score, peak nasal inspiratory flow (PNIF), and acoustic rhinometry (ARM). The nasal tryptase and sIgE-Dp were measured at baseline and 15 min and 1 h after a positive NAPT-Dp. Two allergic rhinitis (AR) patients were used as positive controls. Results: Fifty-four NAR children (61.1% boys) with the mean ± SD age of 11.1 ± 2.1 years were enrolled. The median duration of disease was 6.3 years. The most frequent comorbidity was asthma (38.9%). Eighty-seven percent of patients had mild persistent severity. NAPT-Dp was positive in 2/54 (3.7%) of NAR children who had increased symptom score and decreased minimal cross-sectional area (MCA) on ARM as well as PNIF. However, there was no change in the nasal tryptase and sIgE-Dp. The control AR patients had positive NAPT-Dp and increased nasal tryptase at 15 min without the change of sIgE-Dp. Conclusion: LAR is an uncommon condition in children. Further investigation in a large population of children with NAR is needed.