The primary objective is to assess the concentration of each allergen extract (Phleum pratense and Dactylis glomerata) that induces a wheal size equivalent to that produced by a 10 mg/mL histamine dihydrochloride solution. The standardization procedure is carried out according to the Aas Method as specified in the guideline developed by the Nordic Council on Medicines
The trial will consist of a single visit, in which the following procedures will be carried out: * Demographic data (age, race, and gender). * Medical history: Time of onset of allergic rhinitis, rhinoconjunctivitis, allergic asthma and sensitizations (positive skin prick test) to allergens other than Phleum pratense and Dactylis glomerata. * Inclusion/exclusion criteria. * Physical examination (Cardiovascular, pulmonary, neurobiological, gastrointestinal, dermatological, other body systems and height, weight). * Pregnancy test. Women of childbearing age will undergo a urine pregnancy test. * Performance of prick-tests (3 concentrations of Phleum pratense and Dactylis glomerata allergenic extracts, positive control and negative control). * Collection of blood sample (20 mL) from the subjects to create a pool of sera for the "in vitro" standardization of the allergenic extracts. Each serum sample will be stored in a tube labeled with the subject number and frozen. These serum samples will remain in the freezer until the end of the study. 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 tests necessary to standardize and characterize this extract and produce its corresponding IHRP (In-house reference preparation), as indicated by the Royal Spanish Pharmacopoeia and the European Pharmacopoeia. In addition, it will be 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. * Assesment of adverse events. The trial will also include a follow-up call 72 hours after the prick tests are performed to monitor possible adverse events.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
OTHER
Masking
NONE
Enrollment
31
In each subject, a drop of each of the 3 concentrations of the allergenic extract, in addition to the positive control (histamine) and the negative control, will be applied. The application will be duplicated on the subject's anterior forearm, with a distance of approximately 4 cm between each application to avoid overlapping reactions and false-positives results.
Clínica de Asma y Alergia Dres. Ojeda
Madrid, Spain
Skin induced wheal measurement
Measure of the area (mm\^2) of the induced wheal on the skin upon applying each of the 3 concentrations of each allergenic extract (Phleum pratense and Dactylis glomerata), as well as those induced by positive (histamine) and negative controls, through the prick test.
Time frame: 15 minutes after allergen introduction
Adverse events registration
Registration of any adverse events that occurred during the course of the trial
Time frame: Through study completion, an average of 6 months
Adverse reactions registration
Registration and documentation of any adverse reaction that occurred during the course of the trial
Time frame: Through study completion, an average of 6 months
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