Purpose of review: To reflect on and discuss the recent evidence of reliability of the challenge chamber results for real life, especially focusing on the validation of allergen concentrations being ‘physiologic’ and generating symptoms in the exposed volunteers comparable to the natural exposure during pollen season and to the home environment.
Recent findings: Publications of the last 18 months covered by this review focus on the validation of allergen chamber systems, especially on the quantitative comparison of environmental allergen exposure with allergen challenge chamber (ACC) exposure. It highlights new evidence on the question of relevance of environmental and experimental priming effects and discusses the selection of relevant parameters for the quantification of treatment effects.
Summary: Benchmarks for validating the ACC systems have been defined and are referred to in clinical ACC trials in increasing amount. So the level of evidence concerning the validity and reliability of allergen chamber systems is steadily growing, especially in allergen-specific models, priming effects and reproducibility of results in the same study population at different time points and with different challenge systems.