Local allergic conjunctivitis: a phenotype of allergic conjunctivitis

Area of Science:

• Ophthalmology
• Allergology
• Immunology

Background:

• Local allergic rhinitis (LAR) is recognized in otolaryngology, but local allergic conjunctivitis (LAC) is less studied in ophthalmology.
• Divergent results between total IgE in tear fluids (t-tIgE) and serum (s-sIgE) in suspected allergic conjunctivitis patients are observed.
• Japanese guidelines for allergic conjunctival diseases involve testing t-tIgE and s-sIgE.

Purpose of the Study:

• To investigate the concept of local allergic conjunctivitis (LAC) in ophthalmology.
• To explore the significance of divergent t-tIgE and s-sIgE results, potentially indicating LAC.
• To differentiate between IgE-mediated and non-IgE-mediated allergic conjunctivitis.

Main Methods:

• 148 patients with allergic conjunctivitis symptoms were included.
• Tear IgE (t-tIgE) measured using Allerwatch Tear IgE®.
• Serum IgE (s-sIgE) measured using ImmunoCAP Rapid® and View Allergy 39®.
• Conjunctival cytology was performed to detect eosinophils.

Main Results:

• 56.1% of patients were positive for t-tIgE.
• 16.9% of t-tIgE positive patients had no detectable s-sIgE, suggesting possible LAC.
• In cases negative for both t-tIgE and s-sIgE, conjunctival scraping revealed eosinophils in some, indicating potential non-IgE-type allergic conjunctivitis.

Conclusions:

• The study provides evidence supporting the existence of local allergic conjunctivitis (LAC).
• LAC is proposed as a distinct phenotype of allergic conjunctivitis.
• Further research is warranted to fully characterize LAC and its clinical implications.