9. Inability or unwillingness to stop using drugs that may inhibit the ability to treat a severe allergic adverse event. This includes, but is not limited to; beta blockers such as atenolol (Tenormin), metoprolol (Lopressor, Toprol-XL) and propranolol (Inderal, Inderal LA) for 48 hours prior to Visit 1 and for the duration of the study. All subjects must be off of antihistamine therapy 7 days before skin testing.