Intranasal allergen challenge during corticosteroid treatment

Area of Science:

• Allergy and Immunology
• Pharmacology
• Otorhinolaryngology

Background:

• Allergic rhinitis, commonly known as hay fever, significantly impacts quality of life.
• Corticosteroids are widely used for managing hay fever symptoms.
• The precise mechanisms of intranasal corticosteroid efficacy in Type I allergic reactions require further elucidation.

Purpose of the Study:

• To investigate the effect of intranasal beclomethasone dipropionate on immediate Type I allergic reactions in the nasal mucosa.
• To compare the efficacy of beclomethasone dipropionate against placebo in a controlled setting.

Main Methods:

• A double-blind, placebo-controlled, cross-over trial involving eighteen hay fever patients.
• Daily intranasal administration of 800 mcg beclomethasone dipropionate for one week.
• Nasal allergen challenge performed on the final day of each treatment period.

Main Results:

• Beclomethasone dipropionate treatment showed a trend towards diminished sneezing and rhinorrhoea, but results were not statistically significant (P=0.10).
• Immediate nasal blockage was not significantly affected by steroid treatment.
• A discrepancy exists between the study's findings on immediate reactions and the drug's known clinical efficacy in hay fever.

Conclusions:

• The minor effect on immediate reactions may be due to the significance of delayed reactions in hay fever.
• Continuous allergen exposure in natural settings might potentiate the steroid's effect compared to single provocations.
• Beclomethasone dipropionate's efficacy in hay fever may involve mechanisms beyond immediate allergen-induced responses, possibly through inhibition of end-organ priming.