Background: Allergic rhinitis is a common problem involving activation of nasal mast cells and irritability. The hypothalamic-pituitary-adrenal (HPA) axis is stimulated in cases of emotional or environmental stress, and mast cells have been implicated in stress-induced immune responses.
Objective: To investigate whether intranasal challenge of patients allergic to a single antigen would stimulate the HPA axis.
Methods: Plasma corticotropin and cortisol levels were measured 20, 40, 60, 80, 100, and 120 minutes after intranasal antigen administration in healthy volunteers (n=3) and in patients with rhinitis who are allergic to Parietaria (n=10).
Results: Mean +/- SD corticotropin levels were 24.43 +/- 14.38 pg/mL in patients compared with 8.83 + 5.02 pg/mL in controls, and this increase was statistically significant (P = .049). Patient cortisol levels also increased to a mean +/- SD of 8.87 +/- 4.90 pg/mL (at 40 minutes) compared with 4.36 +/- 1.72 pg/mL in controls (P = .11 due to 1 outlier). Compared with individual patient prechallenge levels, corticotropin levels increased in 7 patients and cortisol levels increased in 5 at 40 minutes.
Conclusion: These results suggest that allergic rhinitis may activate the HPA axis. A larger study with additional controls is required for definitive conclusions.