Subjects with allergic asthma developing the required nasal symptoms in response to nasal allergen titration during a screening period will be randomized 1:1 to one of 2 cohorts. All subjects will have repeated nasal challenges with allergen. One cohort will have nasal saline challenge as control. One cohort will have intranasal corticosteroid intervention.

Eligible subjects will be randomized 1:1 to Cohort A or Cohort B. Each cohort will undergo 3 nasal challenges, each separated by 3 weeks. Cohort A will undergo 2 nasal allergen challenges, and 1 nasal diluent challenge. TNSS, PNIF, spirometry, and samples of blood, urine and nasal secretions will be collected until 24h post-challenge to assess reproducibility. Cohort B will undergo 3 nasal allergen challenges; one of the challenge will be conducted after 14 days treatment with placebo, and one challenge will be conducted after 14 days treatment with triamcinolone acetonide aqueous nasal spray at a dose of 220 mcg administered twice daily for a total daily dose of 440 mcg. TNSS, PNIF, spirometry, and samples of blood, urine, nasal secretions will be collected until 24h post-challenge to determine reproducibility, and nasal tissue will be collected 24h post-challenge to determine effect of steroid treatment.

Inclusion Criteria:

• allergic rhinitis + mild asthma

Exclusion Criteria:

• other respiratory disease
• any medication for treatment of asthma/allergic rhinitis with the exception of infrequent beta-2 agonist.