The objective of this study is to determine the biological activity of Quercus illex and Quercus robur allergen extracts in histamine equivalent prick (HEP) units, in order to be used as in-house reference preparation (IHRP).

The trial will consist of a single visit, in which the following procedures will be carried out:

• Demographic data.
• Clinical history.
• Inclusion/exclusion criteria.
• General examination.
• Performance of prick-tests (3 concentrations of Quercus ilex allergenic extract, 3 concentrations of Quercus robur allergenic extract, positive control and negative control).
• Obtaining a blood sample from the patient to create a pool of sera for the "in vitro" standardization of the allergenic extract. This pool of sera is necessary for the characterization of the Company's standard. Each serum sample will be stored in a tube that will be labeled with the subject number and frozen. These serum samples will remain in the freezer until the study is completed. When the study is completed, they will be transported to the laboratory, where all sera will be pooled. This "pool" of sera will be used to perform the complementary in vitro standardization tests. These include ELISA for measurement of inhibition against specific IgE, etc. These serum samples are not destroyed. They are pooled together to form a pool that will be used, as described in the previous paragraph, in all the in vitro tests necessary to standardize and characterize this extract and produce its corresponding HIRP (In-house reference preparation), as indicated by the Royal Spanish Pharmacopoeia and the European Pharmacopoeia. This pool of sera is not destroyed, it is used in the in vitro analyses necessary for the standardization of new batches of this allergenic extract. Once the pool has been formed, the tubes containing the original serum samples are destroyed.
• Evaluation of adverse events.

Inclusion Criteria:

• Subjects must live in a geographical area where allergic problems caused by Quercus ilex and Quercus robur are relevant.
• Positive clinical history of inhalant allergy (rhinitis and/or rhinoconjunctivitis and/or asthma) to asthma) to Quercus ilex and Quercus robur.
• A positive prick-test (mean papule diameter ≥ 3 mm) with an extract of the same allergen and/or presence of specific IgE against that allergen.
• The mean papule area obtained with Histamine dichlorhydrate at 10 mg/mL should be ≥ 7 mm2.
• Age: Between 18 and 64 years old.
• Subjects must be able to give informed consent.

Exclusion Criteria:

• Subjects should not be excluded in terms of low or high sensitivity to Quercus ilex and Quercus robur.
• Subjects outside the age range.
• Subjects who have previously received immunotherapy in the last 5 years for the treatment of asthma or rhinoconjunctivitis for the treatment of asthma or allergic rhinoconjunctivitis induced by allergens that may interfere with Quercus ilex and Quercus robur extracts.
• Subjects with significant symptoms of rhinoconjunctivitis and/or bronchial asthma in which the suspension of the systemic antihistamine treatment is contraindicated.
• Subjects who have previously presented a severe secondary reaction during the performance of diagnostic skin tests by prick test.
• Subjects under treatment with ß-blockers.
• Subjects clinically unstable (acute asthma, febrile, etc.).
• Subjects with active urticaria lesions, severe active dermographism, severe atopic dermatitis, sunburn, eczema, psoriasis lesions in the area where the prick test is performed (risk of false positives).
• Subjects with active viral infection by herpes simplex or herpes varicella zoster in the area where the prick test is performed.
• Subjects with any pathology in which the administration of adrenaline is contraindicated (hyperthyroidism, HTA, cardiopathy, etc.).
• States of the subject in which he/she cannot offer cooperation and severe psychiatric disorders.
• Pregnant women or women at risk of pregnancy and lactating women.