Nasal challenge with allergen leads to maxillary sinus inflammation

Background

Allergic rhinitis and chronic rhinosinusitis are both characterized by chronic inflammation.

Objective

We sought to investigate the effect of nasal allergen challenge on the maxillary sinus and study the effect of premedication with loratadine.

Methods

We performed a double blind, crossover, randomized, placebo-controlled study in 20 allergic subjects out of season. After treatment with either placebo or loratadine (10 mg PO daily) for 1 week, a catheter was inserted into one maxillary sinus and used to lavage the cavity. The subjects then underwent nasal challenge with diluent for the allergen extract, followed by 3 concentrations of grass or ragweed. Nasal and ipsilateral sinus lavages were performed after each challenge and then hourly for 8 hours. Sneezes and symptoms were recorded, and the lavage specimens were evaluated for eosinophils and levels of eosinophil cationic protein, albumin, and histamine. Eleven of the subjects underwent a similar challenge with lactated Ringer's solution.

Results

Compared with the lactated Ringer's solution challenge, allergen challenge resulted in significant increases in most early- and late-phase nasal parameters. Allergen challenge of the nose also led to a significant increase compared with control values in maxillary sinus eosinophils and the levels of albumin, eosinophil cationic protein, and histamine during the late response. Loratadine resulted in significant inhibition of the nasal early response compared with that seen with placebo (P < .05).

Conclusion

These findings suggest that a neural reflex or systemic allergic inflammation is responsible for the sinus inflammatory response and that this inflammatory response might play a role in the development of rhinosinusitis in allergic subjects.

Key words: Allergic rhinitis, chronic rhinosinusitis, allergen challenge, eosinophils, maxillary sinus, reflex

Abbreviations used: ECP, Eosinophil cationic protein, EPR, Early-phase response, LPR, Late-phase response, LR, Lactated Ringer's