EAACI Position paper on the standardization of nasal allergen challenges.

Nasal allergen challenge (NAC) is an important tool to diagnose allergic rhinitis. In daily clinical routine, experimentally, or when measuring therapeutic success clinically, nasal allergen challenge is fundamental. It is further one of the key diagnostic tools when initiating specific allergen immunotherapy. So far, national recommendations offered guidance on its execution; however, international divergence left many questions unanswered. These differences in the literature caused EAACI to initiate a task force to answer unmet needs and find a consensus in executing nasal allergen challenge. On the basis of a systematic review containing nasal allergen challenges of the past years, task force members reviewed evidence, discussed open issues, and studied variations of several subjective and objective assessment parameters to propose a standardized way of a nasal allergen challenge procedure in clinical practice. Besides an update on indications, contraindications, and preparations for the test procedure, main recommendations are a bilaterally challenge with standardized allergens, with a spray device offering 0.1 mL per nostril. A systematic catalogue for positivity criteria is given for the variety of established subjective and objective assessment methods as well as a schedule for the challenge procedure. The task force recommends a unified protocol for NAC for daily clinical practice, aiming at eliminating the previous difficulty of comparing NAC results due to unmet needs.

[Occupational asthma and rhinitis: challenge tests and nasal hyperactivity: present practice and future perspectives]. / Asthmes et rhinites professionnels: tests réalistes et hyper-réactivité nasale: pratique actuelle et perspectives d'avenir.

Nasal hypersensitivity is defined by an exaggerated response to certain specific stimuli such as a work-related agent, non-specific stimuli (irritant effect), or to allergic or inflammation mediators. The study of nasal hypersensitivity always involves provocation tests with other practical assays. In the occupational context, the provocation test most routinely used are "challenge tests", carried out with suspected substances provided by the patient, and non-specific tests with mediators (histamine and carbachol). Three complementary techniques-rhinomanometry, intranasal expiratory flow, and nasal lavage with cell and mediator studies, aim at three objectives. These are principally diagnostic and physiopathological, but are also possibly therapeutic. The authors describe in detail the technique of passive anterior rhinomanometry, nasal challenge tests and cholinergic challenges leading to a better understanding of non-specific nasal hypersensitivity. Future prospects concern the establishment of dose-response reactivity curves, exploration of the intranasal expiratory flows and research into nasal lavages with the study of cells and mediators released.