Evaluation of an Adjusted Cutoff Value for S.P.A.T (Skin Prick Automated Test) Device in Allergic Subjects

Inclusion criteria

• Provide informed consent signed by study patient and investigator;
• Subjects with Health Social Identification Number;
• Allergic subjects with rhinitis with or without asthma and with or without conjunctivitis symptoms with proof of sensitisation to an inhalant allergy, either house dust mite ( Dermatophagoides pteronyssinus) or birch pollen by a positive skin prick test (SPT) with a wheal diameter ≥3 mm as compared to negative control. The clinical response against the culprit allergen will be assessed by a positive nasal allergen provocation test. (patients must not have clinical symptoms corresponding to both sensitization).
• Non-allergic subjects with proof of lack of sensitisation to any of the above referred allergens by a negative conventional skin prick test less than 2 years.
• Normal lung function as judged by investigator with FEV 1 and FEV 1/FVC ≥ 70% of predicted
• Willing and able to comply with clinic visits and study-related procedures;
• Able to understand and complete study-related questionnaires.

Exclusion criteria

• Skin pathology like chronic or exuberant urticaria, dermographism, chronic dermatitis that needs daily treatment;
• Any skin abnormalities, which could negatively - in the opinion of the investigator - affect the test results, including large scars and tattoos on the forearm ;
• Patients with clinical symptoms corresponding to both sensitization to birch and house dust mite
• Use of antihistaminic medication < 7 days before the start of the study;
• Use of tricyclic antidepressants (antihistamine activity) < 7 days before the start of the study;
• Use of topical (on the forearm) or systemic corticoids < 7 days before the start of the study;
• Use of any monoclonal antibodies such as omalizumab, dupilumab, mepolizumab < 6 months before the start of the study;
• Use of oral systemic corticosteroids within 4 weeks prior to screening
• Use of intramuscular systemic corticosteroids within 3 months prior to screening
• Use of allergen immunotherapy for the allergen tested (<2 y) or another inhalant allergen;
• Pregnancy or breastfeeding;
• Women without highly effective contraception (hormonal contraception, intrauterine device, bilateral tubal occlusion/ligation, vasectomized partner, sexual abstinence) at least one month prior to inclusion and during the study;
• Incapacitated subjects;
• Subjects who do not speak the local language (French);
• Subjects who cannot read or write.