Biological Standarization of Cupressus Arizonica Allergen Extract to Determine the Biological Activity in Histamine Equivalent Units (HEP)

Inclusion Criteria: * Subject has provided written informed consent, appropriately signed and dated by subject. * Subject can be male or female of any race and ethinic group. * Age 18 years and 60 years ata the study inclusión day. * Positive clinical history of inhalatory allergy to Cupressus arizonica. * A positive prick test with a standarices commercially Cupressus arizonica allergen extract. * A positive prick test with positive control of histamine 10 mg/ml. * A positive test for specific IgE to Cupressus arizonica. Exclusion Criteria: * Immunotherapy in the past 5 years with an allergen extract Cupressus arizonca or other allergen extract than may interfere with the allergene to be tested. * Use of drugs that may interfere before and after with the skin reactions. * Treatment with certain drugs.