Contactallergie voor oogdruppels met β-blokkers

In six patients (4 women aged 80, 62, 43 and 52 years and 2 men aged 58 and 51 years), who used eyedrops containing β-blockers for the treatment of glaucoma, allergic contact dermatitis of the eyelids was diagnosed. Three were allergic to metipranolol, 2 to levobunolol and 1 to timolol. In literature, less than 50 cases of hypersensitivity to β-blockers in eye medication have been reported. There are, however, reasons to assume that sensitization is more frequent: (a) not all patients are referred by the ophthalmologist to the dermatologist; (b) false-negative reactions to patch tests with the commercial preparations and with β-blockers are not infrequent; (c) they are not routinely tested because β-blockers are difficult to obtain in pure form; (d) cross-reactions with other β-blockers are infrequent, and changing to another preparation therefore usually solves the clinical problem. Nevertheless it is advisable to test a battery of β- blockers (befunolol, levobunolol, metipranolol, timolol) in allergic patients. A test preparation of 2% in water or 3%-10% in petrolatum may be suitable. Control testing in non-exposed individuals is necessary to exclude irritation reactions.