Nasal challenge testing in grass pollen hay fever

Area of Science:

• Allergen immunotherapy
• Clinical immunology
• Rhinology

Background:

• Hay fever, or allergic rhinitis, is commonly caused by grass pollen.
• Accurate assessment of nasal allergen sensitivity is crucial for diagnosis and management.

Purpose of the Study:

• To evaluate nasal sensitivity to rye grass pollen allergens using nasal airways resistance (NAR) measurements.
• To assess the reproducibility of nasal provocation testing over different time points.

Main Methods:

• Nasal provocation testing with Lolium perenne (rye grass) allergens in 24 hay fever patients.
• Measurements included nasal airways resistance (NAR), sneezing, and rhinorrhea.
• Testing was conducted during and after the pollen season, and in early winter.

Main Results:

• Threshold doses to induce a twofold increase in NAR or symptoms were slightly higher immediately after the pollen season.
• No significant differences in threshold doses were observed between the pollen season and 8 months later.
• Late allergic reactions occurred in 4 of 24 patients when threshold doses were exceeded.

Conclusions:

• Nasal provocation testing is a reproducible method for assessing rye grass pollen sensitivity.
• Seasonal variations in nasal allergen sensitivity are minimal, suggesting year-round management may be necessary.
• Late-phase reactions can occur following nasal allergen challenge.