Allergic Contact Dermatitis to Both Latanoprost and Dorzolamide in Eye Drops

Allergic contact dermatitis (ACD) to ophthalmic medication is rare, with a prevalence of 0.7% to 1% in patch test populations [1, 2]. This is the first case of allergic contact dermatitis to both latanoprost and dorzolamide in the same patient. A 74-year-old woman, with a history of glaucoma and breast cancer surgery in 1998, reported an erythematous and scaly palpebral eruption, associated with intermittent itching and episodes of significant oedema and swelling, for the past 18 months (Figure 1). The rash appeared following the introduction of two eye drops: Xalacom (Timolol and Latanoprost) and Trusopt (Dorzolamide). The lesions resolved within a week after applying a topical corticosteroid. The eye drops were then discontinued, and Geltim (Timolol) was introduced, with no recurrence of the eczema. Patch tests were performed with the European baseline, cosmetic series, (Chemotechnique Diagnostics, Vellinge, Sweden) and Xalacom, Trusopt and Geltim as is. Patch test chambers used were IQ ultra (Chemotechnique Diagnostics, Vellinge, Sweden) fixed with Hypafix (BSN Medical, Stockholm, Sweden), for 48 h. Readings, performed on day (D) 2 and D4 according to ICDRG criteria [3], showed a positive reaction to Xalacom and Trusopt ‘as is’ (+) (Figure 2) while patch test with Geltim ‘as is’ was negative. It is important to note that patch test to benzalkonium chloride 0.1% pet was also tested and yielded a negative result. The patient continued using Geltim for several months without further episodes of eczema. One year later, due to treatment failure and recurrence of ocular hypertension, her ophthalmologist switched Geltim to Dualkopt (Timolol and Dorzolamide), which led to a recurrence of periorbital eczema. Repeated open tests (ROAT) performed with Dualkopt and Geltim were positive at D1 for Dualkopt only (Figure 3), confirming the allergy to Dorzolamide. Allergic contact dermatitis (ACD) of the eyelids is a well-known adverse reaction to topical medications used in the treatment of glaucoma [1, 2]. Among the various medications implicated, latanoprost, a prostaglandin analog, and dorzolamide, a carbonic anhydrase inhibitor, have both been previously reported to cause allergic contact dermatitis [4-11]. Prostaglandin analogs like latanoprost are frequently associated with ocular side effects, including hyperemia, irritation, and periorbital dermatitis. Similarly, dorzolamide has been reported to cause dermatologic reactions such as periorbital eczema or irritation, particularly with prolonged use. For example, Matei et al. have recently reported an eyelid contact dermatitis to Cosidime (containing Dorzolamide) after 2.5 years of continuous use [12]. Although individual cases of ACD caused by either latanoprost or dorzolamide have been documented, dual sensitization to both agents has never been reported before. Dual sensitization cases are rare, with only two cases involving both timolol and dorzolamide [13] and dorzolamide with benzalkonium chloride [14]. A recent larger study [15] reported that contact allergy to a topical ocular allergen or medication was found in 12.9% of patients (41 out of 318). Among these, only 11 patients reacted to two allergens, and just two patients reacted to three or more allergens. Patch test positive patients were often previously diagnosed with cataract (29.3%) or glaucoma (24.4%), and the majority reported more than one previous reaction. Initial symptoms were oedema (56.0%), erythema (48.8%) and dermatitis (31.7%) in the eye region, and facial dermatitis was also reported. This case highlights the importance of considering multiple culprits in patients presenting with periocular eczema, particularly when exposed to combination glaucoma therapies. Clinicians should remain vigilant when managing glaucoma in patients with a history of allergic reactions, as multiple agents within the same therapeutic regimen may be responsible for the observed dermatologic manifestations. This case emphasises the need for careful drug history review and consideration of contact allergies in the differential diagnosis of eyelid dermatitis. It also underscores the necessity of individualised treatment plans for glaucoma patients with a predisposition to allergic skin reactions—such as an atopic background, previous contact dermatitis from eye drops, or long-term eye drop use—possibly requiring alternative therapeutic strategies. Antoine Badaoui: conceptualization, investigation, writing – original draft, writing – review and editing. The patient gave her consent to publish the picture. The author declares no conflicts of interest.