Cellular sensitivity in allergic blepharoconjunctivitis due to phenylephrine eye drops

Classification of ocular allergy

PURPOSE OF REVIEW

The purpose of this article is to summarize the clinical presentations associated with the classification of ocular allergy. This article also serves to summarize recent findings of pathophysiological mechanisms associated with ocular allergy and to highlight recently improved diagnostic methods for ocular allergic inflammation.

RECENT FINDINGS

The term allergic conjunctivitis may not sufficiently describe all forms of allergic eye disease, thus a new classification system is desirable, preferably derived from the varied pathophysiological mechanisms operating in the different forms of ocular allergy. Recent published material has further characterized the roles that inflammatory and structural cells have in ocular allergic inflammation. Improved diagnostic methods have also been developed to assess the underlying causes of ocular allergy.

SUMMARY

The underlying immune responses of ocular allergies are complex, indicating the critical need to understand the pathophysiology behind these diseases. Extensive research over the past several years has provided valuable insight into understanding the pathophysiology associated with the different forms of allergic conjunctivitis. Further clarification of the mechanisms associated with different forms of ocular allergy is essential for improved methods of classification, diagnosis, and treatment.

Eyedrop‐Induced Allergy: Clinical Evaluation and Diagnostic Protocol

BACKGROUND

In the last few years, adverse reactions to mydriatic eyedrops have been investigated. However, is not still available a standardized protocol, capable of identify the pathogenetic mechanism. In the light of these findings we have evaluated the reliability of a protocol with well established concentration of specific allergens.

METHODS

The diagnostic method includes the application of patch test series Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali (GIRDCA), medicaments, corticosteroids, local anesthetics, main eyedrops' excipients, pure active principles and extemporaneous preparations with mydriatic eyewashes. At the same time, skin prick test with a solution of atropine sulfate at 1 per thousand and an intradermal test with injection of atropine at 0.01 per thousand were carried out.

RESULTS

After patch tests were removed, we detected seven positiveness to the phenylephrine, two to the benzalkonium chloride, one to thiomersal, one to the ethylendiamine and one to the atropine sulfate 1 per thousand. With intradermal tests we obtained three positiveness in patients who reported adverse reactions to atropine.

CONCLUSIONS

Our results show that phenylephrine is frequently responsible for allergic conjunctivitis (53.8%). In the case of atropine, even though the limited number of patients suggests to perform more extensive studies, it emerges that our diagnostic protocol is safe and might be able to screen allergic reactions in the field of ophthalmopathies.