Dermatological reactions to ophthalmic preparations: More than meets the eye

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

BACKGROUND

The 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.

OBJECTIVE

This 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.

METHODS

We 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.

RESULTS

In 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.

CONCLUSIONS

One 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.

A closer look at allergic contact dermatitis caused by topical ophthalmic medications

BACKGROUND

Allergic contact dermatitis caused by topical ophthalmic medications (OftACD) is frequently difficult to confirm with patch testing and, therefore, it is considered uncommon.

METHODS

We collected retrospective data from a cohort of 65 patients with suspected OftACD patch tested in our Dermatology Unit (2005-2021) according to ESCD guidelines, using a series of topical drugs and excipients (Chemotechnique Diagnostics), including betaxolol and timolol 5% pet. kindly supplied by the pharmaceutical industry. Also, frequently used ophthalmic medications as well as patient's own products were also patch tested 'as is' in most patients.

RESULTS

Positive patch tests to ophthalmic medications occurred in 44 patients (67.7%) (38F/6M; mean age 63.1 years), with 102 positive reactions. Most positive reactions were associated with active ingredients (n = 56), especially aminoglycoside antibiotics (n = 27), followed by excipients (n = 24) such as sodium metabisulfite (n = 7). There were also positive reactions to topical products tested 'as is' (n = 22), mostly containing beta-blockers, but only five of these reacted to the active ingredient.

DISCUSSION

This study reinforces previous findings in OftACD, such as older age of onset, and the importance of antibiotics, contrasting with the progressively lower prevalence of excipients. In addition, it helps raising awareness for the sensitization to beta-blockers, which is probably underestimated. Patch test preparations for the diagnosis of OftACD may require protocol optimization.

A Single Drop in the Eye - Effects on the Whole Body?

Introduction:

Although the local adverse effects of ophthalmic drugs, including allergic reactions, are well recognized, less is known about the systemic side- effects of eye drops, especially during pregnancy, breast-feeding and early childhood. Ophthalmologists should also be aware of unusual, in some cases even life-threatening, effects of commonly used eye drops.

Conclusion:

This brief review outlines the routes of systemic absorption and the kinetics of active components present in eye drops, and identifies the clinically relevant systemic adverse effects.