Does Fluticasone Propionate Reduce the Late Allergic Reaction When the Drug is Given Post-allergen?

The investigators propose a 3-treatment, placebo-controlled, double-dummy, double-blinded, randomized, crossover study in which single doses of placebo, will be compared to Fluticasone propionate (Flovent Diskus) 250 mcg and budesonide 400 mcg administered after allergen challenge, at cessation of the early allergic reaction (at 20% fall in FEV1 from post-allergen peak)