To determine the minimum amount of Dermatophagoides pteronyssinus allergen extract producing a positive skin reaction.

Recruitment & Eligibility

Status: ot Recruiting

Sex: All

Target Recruitment: Not specified

Inclusion Criteria

- Positive clinical history of allergy with respiratory symptoms
(rhinitis and / or rhinoconjunctivitis and / or asthma) against Dermatophagoides pteronyssinus.
-Subject has provided written informed consent, appropriately signed and dated by the subject (or legal representative, if applicable).
-Subject can be male or female of any race and ethnic group.
-Age ?18 years and ? 60 years at the study inclusion day.
-Positive skin prick test with a standardized commercially available
preparation of Dermatophagoides pteronyssinus allergen extract. The skin prick test will be considered positive if the test results in a wheal major diameter of at least 3 mm or an area at least 7 mm2. Positive skin prick test results are valid if performed within one year prior to the inclusion of the subject in the study
-A positive test for specific IgE to Dermatophagoides pteronyssinus (CAP-RAST major or equal to 2). IgE results are valid if performed within one year prior to the inclusion of the subject in the study.
Are the trial subjects under 18? no
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 30
F.1.3 Elderly (>=65 years) no
F.1.3.1 Number of subjects for this age range

Exclusion Criteria

-Immunotherapy in the last 5 years with a allergen extract of Dermatophagoides pteronyssinus or other allergenic extracts of mites that may interfere with the allergen to test due to a high degree of cross-reactivity
-Use of drugs that may interfere with the skin reactions (e.g.,
antihistamines). See Appendix 1 of the protocol
-Treatment with any of the following medications: oral tricyclic or
tetracyclic antidepressants or IMAOs, beta-blockers, chronic use of
corticosteroids or use of oral or parenteral corticosteroids in repeated and intermittent patterns (10 mg/daily of prednisone or equivalent).
-Women who are pregnant or period of breastfeeding and women with a pregnancy test positive during the visit 2, prior to the prick test.
-Dermographism affecting the skin area at the test site at either study visit.
-Atopic dermatitis affecting the skin area at the test site at either study visit.
-Urticaria affecting the skin area at the test site at either study visit.
- Diseases of the immune system relevant clinically, both autoimmune and immunodeficiencies.
-Serious diseases not controlled that may increase the risk for the safety of the subjects involved in this study, including, but not limited to the following: heart failure, uncontrolled or severe respiratory diseases, endocrine diseases, clinically relevant kidney or liver diseases or hematological diseases.
-Participation in any other clinical trial within 30 days (or 5 times the biological half-life of the research of the study product, whichever is longer) prior to the inclusion of the subject in this clinical trial.
-Patients with diseases or conditions that limit the use of adrenaline (heart disease, severe hypertension, ..)
-Severe psychiatric, psychological or neurological disorders
-Abuse of alcohol, drugs or medicines in the previous year.