Local allergic conjunctivitis: a phenotype of allergic conjunctivitis

Local allergic rhinitis (LAR) has been reported in the field of otolaryngology; however, the concept of local allergic conjunctivitis (LAC) has not been widely studied in the ophthalmologic community. We routinely examined total IgE levels in tear fluids (t-tIgE) and antigen-specific IgE levels in serum (s-sIgE) in patients with suspected allergic conjunctivitis, on the basis of Japanese guidelines for allergic conjunctival diseases. There are several cases in which the results of t-tIgE and s-sIgE testing are divergent. We suggest that these divergent cases correspond to LAR in otolaryngology.

The study included 148 patients (33 men and 115 women) with clinical symptoms and signs of allergic conjunctivitis. Allerwatch Tear IgE^® was used for measurement of t-tIgE levels. ImmunoCAP Rapid^® and View Allergy 39^® were used for measurement of s-sIgE levels. Conjunctival cytology using spatula was used to identify eosinophils on the conjunctiva.

A total of 83 patients (56.1%) were positive and 65 patients were negative for t-tIgE in the AW. In the ICR, 97 patients (65.5%) were positive for at least one of the eight allergens, whereas 51 (34.5%) were negative for all allergens. Among 83 patients positive for t-tIgE, 14 (16.9%) had no detectable s-sIgE. Therefore, we considered the possibility of LAC in cases in which only local IgE could be detected. Among 28 cases (18.9%) who were negative for t-tIgE and s-sIgE, 21 underwent conjunctival scraping; eosinophils were found in four cases and eosinophilic granules in two. Accordingly, we considered the possibility of non-IgE-type AC in these six cases.

These results suggest the existence of LAC that is a candidate of a phenotype of AC.