Anti-allergic drug testing in an environmental challenge chamber is suitable both in and out of the relevant pollen season

Responses to ragweed pollen in a pollen challenge chamber versus seasonal exposure identify allergic rhinoconjunctivitis endotypes

“…Foremost, the relative contributions of pollen itself versus additional environmental cofactors in triggering allergic rhinoconjunctivitis during the natural allergy season are unknown. 7,8 Additionally, it is unknown whether participants in one geographic area exposed during the natural season, primarily to different species of given plants, will respond adequately to a single nondominant species being used in environmental chamber studies in multiple geographic sites. For example, in South Texas the dominant ragweed species are giant ragweed (Ambrosia trifida) and false ragweed (Ambrosia acanthicarpa).…”

Allergen exposure chambers: harmonizing current concepts and projecting the needs for the future – an EAACI Position Paper

“…Previous studies of allergen challenges of either grass pollen or HDM show that symptom scores rise over the first 1–2 h and are followed by a plateau phase. The plateau phase indicates that the symptom scores have stabilized, and was therefore considered the more relevant time to analyse the primary outcome . Along with the evaluation period, the calculation of the effect size (e.g., mean and/or AUC) should be reported and justified in the study protocol prior to performance of the study and data analysis. Chamber‐specific placebo (development of symptoms in sensitized patients exposed to allergen‐free air, the so‐called ‘sham run’) and nocebo (development of symptoms due to just seeing chamber subjects with exacerbation of allergic symptoms) effects should be documented as it increases the validity of the exposure tests. Safety measures should be specified in terms of: Selection of subjects suitable for exposure, Prevention of adverse reactions (e.g., by monitoring symptoms and lung function in asthmatic patients), Availability of emergency medical personnel and resuscitation equipment, Availability of nearby emergency room and intensive care facilities, Definition of surveillance procedure following exposure (e.g., late‐phase asthmatic reaction), Reporting of all adverse events and their treatment. …”

Development and validation of an Allergen Challenge Theater for grass and ragweed

“…Accordingly, skin KC TJ barrier dysfunctions permit the penetration of antigens, allergens, toxins, and pollutants through the surface of the epidermis to dermis and subdermal connective and fat tissues. Recent evidence suggests that TJ barrier dysfunction plays a key role not only in atopic dermatitis but also in asthma, allergic rhinitis, chronic rhinosinusitis, and colitis 4. Other data from human and animal studies have shown that impairment of the skin barrier is an important mechanism in allergen sensitization 4.…”

“…Recent evidence suggests that TJ barrier dysfunction plays a key role not only in atopic dermatitis but also in asthma, allergic rhinitis, chronic rhinosinusitis, and colitis 4. Other data from human and animal studies have shown that impairment of the skin barrier is an important mechanism in allergen sensitization 4. Allergic sensitization triggers the first induction of innate immune responses by pathogen recognition receptors on epithelial cells and immune cells, such as innate lymphoid cells (ILCs), dendritic cells, macrophages, and mast cells, and leads to subsequent activation of type 2 immune responses 4.…”