The purpose of this study is to serve as a pilot safety study for the implementation of a new technique for nasal allergen challenges. The new technique consists of having patients maximally inhale to total lung capacity. A nasal metered dose pump will be used to deliver the Dermatophagoides farinae allergen to the nasal mucosa. The patient will not sniff after allergen delivery as in the previous study but instead exhale through the mouth. The investigators propose that this technique will inhibit large amounts of allergen reaching airway mucosa beyond the nasal site of introduction thus limiting serious adverse events.