Exposure of hay fever subjects to an indoor environmental grass pollen challenge system

Abstract

Summary A new indoor nasal allergen challenge system has been developed which allows subjects with hay fever to be exposed to pre‐determined concentration of grass pollen grains in the immediate environment. Thirteen subjects were exposed during the winter months to an atmosphere containing approximately 1000 grains/m3 for 30 min. No changes in nasal airway patency or symptoms of nasal congestion were recorded. It was necessary to increase the pollen concentration to approximately 9000 and 35 000 grains/m3 in two subjects and six subjects respectively, before a positive response was recorded. This response was reproducible in all subjects. Administration of intra‐nasal sodium cromoglycate before exposure significantly inhibited the decrease in nasal airway patency and when administered 1 min before exposure totally abolished symptoms of nasal congestion. This new challenge system may therefore be used as an in vivo screen to assess the potential therapeutic value of drugs in hay fever under controlled conditions.

Rhinitis 2020: A practice parameter update

“…431,435 Nasal cromolyn administered just before allergen exposure can reduce development of symptoms of AR. [440][441][442] Therefore, nasal cromolyn can be useful in short-term prevention of development of episodic AR symptoms if administered just prior to anticipated exposure to an allergen not normally present in a patient's home or work environment. However, there have been no direct comparative trials between intranasal cromolyn and other treatments for such use.…”

A metabolomic, geographic, and seasonal analysis of the contribution of pollen-derived adenosine to allergic sensitization

“…However, pollen is not released continuously and the peak hours are 4–10 times the daily reported average. (Barnes et al 2001; Davies 1985; Skjoth et al 2008). The P2 model uses a factor of 10 to exaggerate the effect.…”

Prediction of the start of the grass pollen season for the western part of the Netherlands

“…Davies & Smith (1973) observed that all pollinosis patients showed symptoms when on a day the number of grass pollen grains (measured on the roof of a London hospital) exceeded 50/m3. Other studies, however, have failed to confirm this (Gro- nemeyer 1967, Connell 1969, Davies 1985. All in all therefore, an unequivocal quantitative relationship between the period with pollinosis symptoms and the grass pollen season remains to be established.…”