Local allergic rhinitis in children: Clinical characteristics and role of basophil activation test as a diagnostic tool

Background: Local allergic rhinitis (LAR) is a condition involving a localized nasal allergic response in absence of systemic atopy. Most studies on LAR have been performed in adults. We aimed to describe clinical characteristics of LAR pediatric patients, its clinical evolution over a 7-year follow-up period and to study the role of basophil activation test (BAT), for its diagnosis. Methods: Forty-four children with non-allergic rhinitis (NAR) were included (24 males, 20 females, aged under 15 years). Nasal allergen provocation test (NAPT) and BAT were performed with Dermatophagoides pteronyssinus and Phleum pratense. Results: Seven patients (16%) were diagnosed of LAR. Six reacted to D pteronyssinus and one to P pratense. All LAR and 86% of NAR patients presented perennial symptoms. Fifty-seven percent of NAR and LAR patients referred persistent symptoms. Around half of NAR and LAR patients reported mild-moderate clinical manifestations. Three LAR patients associated conjunctival symptoms, proportionally more than NAR patients (19%, 7 out of 37). NAR patients presented bronchial asthma (n = 10) more frequently than LAR children (n = 1). More than half of LAR and NAR patients presented family history of atopy. BAT was negative in all LAR patients. On follow-up, 3 LAR patients and 10 of the 25 NAR patients who agreed to be retested, presented systemic sensitization. Dust mites were the most frequent allergen involved. Conclusions: LAR should be ruled out in children with NAR. Almost half of children with LAR develop systemic sensitization over time. BAT shows low sensitivity for the diagnosis of LAR in children.