Local (exclusive) IgE production in the nasal mucosa. Evidence for local allergic rhinitis

IgE production at the site of the nasal mucosa without systemic allergic sensitization in skin tests or in serum represents so-called "local allergic rhinitis (LAR)" as a subgroup of patients with symptoms of allergic rhinitis (AR). Formerly, in case of negative allergological test results, seasonal (intermittent) or perennial (persistent) allergic symptoms have been diagnosed as "non-allergic rhinitis" (NAR). However, there is evidence for specific Th2 cytokine, tryptase, and ECP (eosinophil catonic protein) production in the nasal secretion after allergen exposure in these patients without systemic sensitization. Taking this into account, we recommend performing an allergen-specific nasal challenge and measuring the (local) nasal IgE-levels in addition to standard allergy tests in clinical routine in this subgroup of patients. These tests should be perfomed while or shortly after allergen exposure. In addition, an update of the allergy testing should be performed after a time interval since it has been demonstrated that patients formerly diagnosed with NAR may develop LAR or AR, or patients with LAR may develop AR in the future. The pharmacological therapeutic options in LAR are in line with the treatment of AR. If and to what extent this subgroup of AR patients benefit from allergen-specific immunotherapy (SIT) is currently being evaluated in clinical trials.