Safety and reproducibility of nasal allergen challenge
Funding information
This work was supported by the Institute of Health “Carlos III” of the Ministry of Economy and Competitiveness (National Health Ministry FIS PI17/01410, FIS PI12/00900, FIS PI14/0864, “Sara Borrell” (CD17/0146) and “Rio Hortega” (CM17/00140 and CM17/00141) funding schemes; and grants co-funded by European Regional Development Fund (ERDF): RiRAAF RD07/0064, ARADyAL RD16/0006/000 and ARADyAL RD 16/00006/0018).
Abstract
Background
The nasal allergen challenge (NAC) is a useful tool for the diagnosis of allergic rhinitis (AR) and local allergic rhinitis (LAR) and might serve to design and monitor allergen immunotherapy. Nevertheless, data about its safety and reproducibility are scarce.
Objective
To investigate the safety and reproducibility of NAC in pediatric and adult rhinitis patients with/without asthmatic symptoms, and in healthy controls.
Methods
A retrospective evaluation of the NACs conducted in our Unit for 2005-2017 and monitored by acoustic rhinometry and nasal-ocular symptoms was performed to analyze the safety of two methods for allergen application (metered spray & micropipette) and NAC protocols (NAC with single or multiple allergens/session [NAC-S & NAC-M]). The adverse events (AEs), spirometry values, and rescue medication required for AE were recorded. The reproducibility was examined by a prospective analysis of three repeated NAC-S performed at 1-2-month interval in AR, LAR and nonallergic rhinitis patients, and in healthy controls.
Results
A total of 11 499 NACs were performed in 518 children and 5830 adults. Only four local AE occurred, and 99.97% of NACs were well tolerated. The reproducibility and positive and negative predictive values of three consecutive NAC-S performed in 710 subjects were 97.32%, 100%, and 92.91%, respectively. There were no false-positive results in the 710 analyzed subjects. Safety and reproducibility were comparable between the methods of allergen application and the rhinitis phenotypes.
Conclusion
The NAC is a safe and highly reproducible diagnostic test ready to be used in the clinical practice in both children and adults with or without asthma.
Graphical Abstract
This study evaluates 11 499 Nasal Allergen Challenges (NAC) conducted in 6348 adult and paediatric rhinitis patients and in healthy controls. The NAC is a very safe technique in children and adults and it is highly reproducible when monitored by Lebel symptoms score and acoustic rhinometry. No difference in terms of NAC safety and reproducibility were detected between different allergen application methods or NAC protocols, distinct rhinitis phenotypes, or the presence or absence of asthmatic symptoms.
PPV: Positive predictive value; NPV: Negative predictive value.
CONFLICTS OF INTEREST
The authors declare that they have no conflicts of interest.
