Subjects will be consented, undergo skin testing, medical history questionnaires, and randomized to either placebo or montelukast (10 mg). In one week, subjects return, undergo a blood draw, medical history questionnaires, nasal lavage, and nasal allergen challenge (followed by lavage in 6 hours). Subjects will then cross-over to the other study drug. One week later subjects will undergo a blood draw, medical history questionnaires, lavage, allergen challenge, and repeat lavage (after 6 hours).