Participants will have 2 visits during this study: a screening session and a testing session. At screening, participants will be asked to complete a screening questionnaire and will undergo a targeted physical exam, vital signs measurement, and peak expiratory flow (PEF) testing. Premenopausal women will also have urine collected for pregnancy testing. At the screening session, a 15-minute prick/puncture test will be administered on the skin of the forearm with the proposed standard allergen extract, histamine (positive control), and diluent (negative control). Skin erythema (swelling) response to the injections will be recorded.