Allergic contact dermatitis due to beta-blockers in eye drops: a retrospective analysis of multicentre surveillance data 1993-2004.

Topically applied ophthalmic drugs are a potential cause of allergic contact dermatitis of the periorbital region. The objectives of this study were to assess the frequency and spectrum of contact allergy to topically applied beta-blocker containing eye drops. Data of the Information Network of Departments of Dermatology (IVDK) collected between 1993 and 2004 was analysed. Out of 112,430 patch-tested patients, 332 had been tested with their own topical anti-glaucoma eye drops containing different beta-blockers because of suspected allergic contact dermatitis. The frequency of positive test reactions was related to exposure intensity, as estimated by annual prescription rates in Germany. A total of 43/332 (12.95%) showed at least one positive patch test reaction. Positive reactions were observed to products containing timolol (n = 21), metipranolol (n = 13) and levobunolol (n = 11) without conceivable cross-reactivity. Whereas exposure to beta-blocker-containing eye drops remained stable over the years, as estimated by the prescription rates, a slight, non-significant increase in positive patch-reactions to these substances was noted. This is the first systematic analysis of a large set of data on patients' own beta-blocker topical medications, the results indicating that contact allergy should be considered as important, if rare, adverse event caused by this family of drugs.