ABSTRACT
Apraclonidine is a clonidine derivative with selective a2-adrenergic agonistic activity. Upon ocular administration, apraclonidine enhances aqueous humor uveoscleral outflow and decreases aqueous production by vasoconstriction, thereby decreasing intraocular pressure (IOP). In ophthalmological literature, high percentages of ‘allergy’ to apraclonidine have been reported, up to 48% with apraclonidine 1% eye drops. In Ferrara, Italy, over a 65-month period before 2005, 50 patients affected by periorbital dermatitis while using topical ocular products were patch tested, including with their own ophthalmic medications. A 59-year-old man presented with right sided conjunctivitis and lichenified dry eczema on the right lower eyelid and cheek present for 2 years. Past medical history included glaucoma of the right eye on treatment with timolol eyedrops (applied to both eyes) and apraclonidine eye drops (applied only to the right eye) for 7 years. The positive reaction consisted of erythema and papules which persisted for 7 days. 25 subjects were tested as controls with negative results.
