Local allergic rhinitis: A critical reappraisal from a paediatric perspective.

The so-called local allergic rhinitis (LAR) has been proposed as a phenotype of rhinitis with Th2-driven prominent local allergic inflammation, nasal synthesis of specific IgE and a positive response to a nasal allergen provocation test, in the absence of 'systemic' atopy (negative skin prick test and serum allergen-specific IgE antibodies). To date, available data on LAR are mostly focused on adults. The purpose of this 'Rostrum' was to critically discuss data and implications of the 'LAR concept' in paediatrics. In the natural history of rhinitis due to IgE-mediated reactions triggered by exposure to allergens, a 'LAR' can be either the initial, transient stage of classical allergic rhinitis or a stable phenotype never evolving to 'systemic' IgE sensitization. Given the present difficulties in performing routinely nasal allergen provocation test in children, the development of sensitive and specific tests to detect IgE in the child's nasal secretions is a research priority. We suggest also the hypothetical role of allergen immunoprophylaxis or immunotherapy in LAR. Last, the term 'local allergic rhinitis' may be inappropriate, as rhinitis is always 'local', while IgE sensitization can be either 'local' or 'systemic'.