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.

is the official Journal of the European and International Rhinologic Societies and appears quarterly in March, June, September and December. Cited in Pubmed, Current Contents, Index Medicus, Exerpta Medica and Embase Founded in 1963 by H.A.E. van Dishoeck, Rhinology is a worldwide non-profit making journal. The journal publishes original papers on basic research as well as clinical studies in the major field of rhinology, including physiology, diagnostics, pathology, immunology, medical therapy and surgery of both the nose and paranasal sinuses. Review articles and short communications are also pulished. All papers are peer-reviewed. Letters-to-the-editor provide a forum for comments on published papers, and are not subject to editorial revision except for correction of English language. In-depth studies that are too long to be included into a regular issue can be published as a supplement. Supple ments are not subject to peer-review.