Contact allergy to topical ophthalmic medications: A retrospective single-centre study of three decades

BackgroundThe prevalence of contact allergy to various ophthalmic medications appears to be rare; however, data on culprits, clinical relevance of sensitizations, and changes in frequency within recent decades are limited.ObjectiveThis study aimed to investigate the clinical relevance, risk factors, and prevalence of contact allergy to topical ophthalmic medications in patients suspected of allergic contact dermatitis to ophthalmic medication.MethodsWe retrospectively analysed patch test results and clinical data for 754 patients patch-tested with an ophthalmic medication series at our tertiary referral centre between January 1992 and December 2022.ResultsIn total, 37.5% (283/754) of patch-tested patients had a contact allergy to at least one ophthalmic allergen, with 87.3% (247) being clinically relevant sensitization. Phenylephrine (31.8%, 192/604), povidone-iodine (29%, 27/93), and tobramycin (23%, 46/200) were the most important sensitizers. The incidence of contact allergies increased significantly in a linear manner (p = 0.008) from 20% to 44.1% within the study period. Male sex and age above 40 were risk factors for contact allergy to ophthalmic medication.ConclusionsOne third of patch tested patients had allergic contact dermatitis to ophthalmic medication, particularly phenylephrine. Male sex and age above 40 years were independent risk factors and drove the linear increase in contact allergy to ophthalmic medications within the past 31 years. From 1992 through 2022, 754 patients were patch-tested with ophthalmic medication series. Phenylephrine, povidone-iodine and tobramycin were common culprits and essential for the increase in contact allergies throughout the study period. One-third was diagnosed with allergic contact dermatitis, and the contact allergies were more prevalent among males over 40. image