Intranasal Schirmer Test Shows Promise in Allergy Diagnosis

TOPLINE:

The intranasal Schirmer test (INSCH) may help detect allergic rhinitis during a nasal provocation test. Among patients with allergic rhinitis, the INSCH revealed significantly increased nasal secretions upon exposure to relevant allergens such as mites or birch.

METHODOLOGY:

• The INSCH was performed by attaching Schirmer filter paper — widely used in ophthalmology to measure tears — to each nostril.
• To investigate whether INSCH could objectively assess rhinorrhea during evaluations for allergy, the researchers recruited 50 participants from March 2023 to March 2024.
• Half the participants underwent nasal provocation testing after they had a negative or borderline result for a tested allergen on a skin prick test or specific serum immunoglobulin E test. The other half were in a control group with no history of allergy.

TAKEAWAY:

• Among patients with allergic rhinitis, INSCH wetting distance in significantly increased in the nostril that was provoked with an allergen (mean difference, 13.95 mm; P = .01).
• Individuals with nonallergic rhinitis showed no change in nasal secretions upon provocation with a potential allergen.
• A difference in wetting distance of at least 2.75 mm after provocation had a sensitivity of 81.8% and a specificity of 71.4% in detecting allergic rhinitis.

IN PRACTICE:

“The INSCH could serve as a simple tool in everyday clinical practice to quickly objectify nasal secretion,” the authors wrote.

SOURCE:

Paula von der Lage, MD, with the University of Zurich, Zurich, Switzerland, was the corresponding author of the study, which was published online on May 17 in Annals of Allergy, Asthma and Immunology.

LIMITATIONS:

The study included patients who smoke, despite evidence that smoking can lead to drier nasal mucosa.

DISCLOSURES:

The study received support from the Theodor und Ida Herzog-Egli-Stiftung, Switzerland.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.