Non-specific nasal provocation in children with chronic allergic rhinitis

Area of Science:

• Pediatric Allergy and Immunology
• Rhinology
• Clinical Diagnostics

Background:

• Chronic allergic rhinitis significantly impacts children's quality of life.
• Accurate diagnostic tools are crucial for effective management of pediatric allergic rhinitis.

Purpose of the Study:

• To compare the efficacy of histamine and methacholine nasal provocation tests in differentiating children with allergic rhinitis from healthy controls.
• To assess the safety and tolerability of these provocation tests in pediatric subjects.

Main Methods:

• Twenty-three children with allergic rhinitis and eleven healthy controls underwent serial nasal provocation with increasing concentrations of histamine and methacholine.
• Total nasal resistance was measured using active anterior rhinomanometry.
• Spirometry (FEV and FVC) was assessed, and symptoms were recorded.

Main Results:

• Both histamine and methacholine increased nasal resistance with rising concentrations.
• Histamine provocation showed higher sensitivity (91%) and positive predictive value (80.8%) in identifying allergic rhinitis compared to methacholine (55% sensitivity, 75% positive predictive value).
• No correlation was found between provocative concentration and symptoms, and spirometric values remained unchanged. Both agents were well-tolerated.

Conclusions:

• Histamine nasal provocation is a more adequate and sensitive method for diagnosing allergic rhinitis in children.
• Methacholine provocation is less effective in differentiating allergic rhinitis from non-atopic controls in this pediatric population.
• Nasal provocation tests with histamine and methacholine are safe and well-tolerated diagnostic procedures for children.