Biological Standardization of Dermatophagoides Pteronyssinus Allergen Extract

This is an open, unblinded and non-randomized biological assay. The study design is a slight modification of the recommendations proposed by the Nordic Guidelines. Three concentrations of Dermatophagoides pteronyssinus allergen extract, together with a positive and negative control, using 10 mg/ml histamine dihydrochloride solution and a glycerinated phenol saline solution, respectively, will be tested in every patient in duplicate on the volar surface of the forearm.