362 Contact Allergy Due to Ophthalmic Drugs in Uruguay

BACKGROUND: The external eye is exposed to a large number of environmental, cosmetic and pharmacological allergens and the frequency of external eye diseases related to the prolonged use of ophthalmic medications and contact lens wear is increasing. Predisposing factors for contact allergy are: high exposure to topical drugs (eyelids & eye), high percutaneous absorption in eyelids, high potential for concomitant irritation and hand transfer of allergens due to frequent rubbing. METHODS: Ninety three patients 56 women and 37 men, age range 10 to 81 years old, mean age 43 years old with a clinical picture compatible with ocular allergy were referred to our Allergy Unit by the Department of Ophthalmology at the University Hospital for allergological evaluation, including a thorough history, complete clinical examination as well as laboratory techniques and skin testing. Patch-testing was performed with the standard series, an ophthalmic series of allergens developed at our unit, as well as additional allergens according to the clinical situation. RESULTS: Contact allergy was more frequently caused by topical antibiotics and preservatives and occasionally by mydriatic agents and topical drugs for glaucoma. The allergens more frequently implicated were Neomycin (10.7%), Bacitracin (9.6%) Thimerosal 8 (8.5%) Benzalconium chloride 5 (5.3%) Phenylephrine hydrochloride 3 (3.2%), local anesthetics 3 (3.2%), Chloramphenicol (3.1%), Polymyxin (2.1%), Kanamycin (2.1%), Gentamicin (2.1%), Tobramycin (2.1%), Beta-blockers 1 (1.7%), and others (6.1%). CONCLUSIONS: Patients with a clinical picture compatible with ocular allergy should be referred for allergologic evaluation. A comprehensive approach will often provide clues for a presumptive diagnosis and appropriate management. When a contact allergy is found it is mandatory to avoid contact with the precipitating substance. This may simply be a case of stopping or altering an ophthalmic medication. The proper use of ophthalmic preparations should decrease the incidence of allergic contact reactions.