Organ‐specific allergen challenges in airway allergy: Current utilities and future directions

Abstract

Atopy has been long used as the screening method for airway allergy. Nevertheless, aeroallergens can trigger respiratory symptoms not only in atopic patients (atopic respiratory allergy, ARA), but also in non‐atopic subjects (local respiratory allergy, LRA). Moreover, ARA and LRA can coexist in the same patient, and this clinical scenario has been called dual respiratory allergy (DRA). When the clinical history cannot determine the relevance of sensitizations in ARA patients, nasal, conjunctival or bronchial allergen challenges (NAC, CAC, and BAC, respectively) should be conducted. Moreover, these tests are required to identify patients with LRA and DRA. The clarification of the allergic triggers of airway diseases has a profound impact on the management strategies the patients can be offered. Importantly, allergen immunotherapy (AIT) remains as the only disease‐modifying intervention for ARA. Recent data indicate that AIT might have a similar effect on LRA patients. Nevertheless, AIT success relies largely on the correct phenotyping of allergic individuals, and NAC, CAC, and BAC are very helpful tools in this regard. In this review, we will summarize the main indications and methodology of CAC, NAC, and BAC. Importantly, the clinical implementation of these tests might translate into precision medicine approaches and better health outcomes for patients with airway allergy.

Utility of silver birch and house dust mite extracts derived from licensed sublingual tablets for nasal allergen challenge

“…6 In a clinical setting, NAC can be helpful to further clarify the diagnosis of rhinitis, especially in patients with a discrepancy between symptoms and allergy tests. 7 The procedure has been shown to be safe, with patients generally demonstrating good tolerance to the process. 8 The efficacy of NAC as a valid tool is critically dependent on the standardization of allergen extracts in terms of their concentration and stability.…”

“… 6 In a clinical setting, NAC can be helpful to further clarify the diagnosis of rhinitis, especially in patients with a discrepancy between symptoms and allergy tests. 7 The procedure has been shown to be safe, with patients generally demonstrating good tolerance to the process. 8 …”

“…NAC is used to explore both the clinical and immunological responses to allergen exposure, 3–5 and it is also applied as a surrogate outcome to evaluate the efficacy of treatments for AR, such as allergen immunotherapy 6 . In a clinical setting, NAC can be helpful to further clarify the diagnosis of rhinitis, especially in patients with a discrepancy between symptoms and allergy tests 7 . The procedure has been shown to be safe, with patients generally demonstrating good tolerance to the process 8 …”