Appropriate Antigen Concentrations and Timing of a Nasal Provocation Test

Area of Science:

• Allergology and Immunology
• Otorhinolaryngology
• Diagnostic Medicine

Background:

• Allergic rhinitis (AR) diagnosis relies on accurate nasal provocation tests (NPT).
• Optimizing NPT parameters, including antigen concentration and evaluation timing, is crucial for reliable results.
• Assessing individual nasal symptoms and peak nasal inspiratory flow (PNIF) aids diagnostic utility.

Purpose of the Study:

• To establish optimal antigen concentrations for NPT.
• To determine the ideal time for evaluating intranasal changes during NPT.
• To analyze the diagnostic value of individual nasal symptoms and PNIF in rhinitis patients.

Main Methods:

• 46 rhinitis patients (19 AR, 27 NAR) underwent intranasal challenge with Dermatophagoides pteronyssinus (DP).
• Initial challenge used 100 AU/mL DP, with subsequent assessments at 15 minutes if significant changes occurred.
• Higher concentrations (1000 AU/mL) and extended timings (30 minutes) were used for non-responders.

Main Results:

• The AR group showed significantly greater changes in visual analogue scale (VAS) for all nasal symptoms, total nasal symptom score (TNSS), and PNIF% 15 minutes after the 100 AU/mL challenge compared to the NAR group.
• Patients in the AR group unresponsive to 100 AU/mL showed minimal differences even after a 1000 AU/mL challenge.
• Receiver operating characteristic (ROC) analysis demonstrated high diagnostic accuracy for VAS changes (AUC ≥0.84), TNSS change (AUC=0.929), and PNIF% change (AUC=0.834) at 15 minutes post-100 AU/mL challenge.

Conclusions:

• The optimal concentration for NPT is 100 AU/mL of DP.
• Evaluating intranasal changes 15 minutes after antigen challenge is the recommended timing.
• Changes in TNSS and PNIF% are effective parameters for diagnosing allergic rhinitis via NPT.