Local specific Immunoglobulin E among patients with nonallergic rhinitis: a systematic review.

BACKGROUND: Allergen specific immunoglobulin can be present in the nasal mucosa of patients with non-allergic rhinitis (NAR). This condition is defined as local allergic rhinitis. However, the reported presence of nasal specific immunoglobulin E (nspIgE) among NAR is variable. The aim of this review was to summarize the studies which reported the presence of nspIgE among patients diagnosed as NAR.

METHODS: Embase (1947- ) and Medline (1946-) were searched until 6th June 2017. A search strategy was utilized to identify studies on nspIgE among patients with NAR. The target population was patients with symptoms of rhinitis, but negative systemic allergen sensitization. Studies with original data on detectable nspIgE among the NAR population were included. Meta-analysis of single proportions as a weighted probability %(95%CI) was performed. Heterogeneity was explored amongst studies.

RESULTS: A search strategy returned 2286 studies and 21 were included. These studies involved 648 participants with NAR. NspIgE was detected using either; 1. nasal secretions, 2. epithelial mucosa sampling, 3. tissue biopsies or 4. In-situ tests. Metaanalysis was performed on studies with nasal secretions. The weighted proportion of detectable nspIgE in nasal secretions within patients with NAR was 10.2 (7.4-13.4) %. Population definitions partly explained variability. Detection of nspIgE was lower in patients without a history suggestive of allergy compared to those with a positive allergic history (0 (0-3.1) % v 19.8 (14.5-25.6) %, p<0.01).

CONCLUSION: NAR with positive allergy history suggests presence of nspIgE. These patients warrant further allergology evaluation to confirm localized nasal allergy, as they benefit from allergy therapy such as immunotherapy.