CD21 Things can only get redder! Two cases of allergic contact dermatitis to topical brimonidine tartrate gel

Abstract Facial erythema is a common and debilitating symptom in rosacea. Brimonidine tartrate gel 0.33% (Mirvaso) is an α2-receptor agonist that targets superficial cutaneous blood vessels causing vasoconstriction. It is approved for the treatment of persistent facial erythema in rosacea and is included in the British Association of Dermatologists rosacea guidelines. Recognized adverse effects including flushing, worsening of erythema and rosacea, and in 2.2% of cases, either irritant or allergic contact dermatitis (ACD) (Moore A, Kempers S, Murakawa G et al. Long-term safety and efficacy of once-daily topical brimonidine tartrate gel 0.5%. J Drugs Dermatol 2014; 13: 56–61). Allergic contact blepharitis to brimonidine eye drops is recognized and, more recently, case reports have described patients developing ACD to topical brimonidine gel [Bangsgaard N, Fischer LAN, Zachariae C. Sensitization to and allergic contact dermatitis caused by Mirvaso® (brimonidine tartrate) for treatment of rosacea – 2 cases. Contact Dermatitis 2016; 74: 378–9]. Here we report two cases of ACD to Mirvaso gel used as a treatment for rosacea. A 27-year-old man presented with a 4-year history of facial redness with associated papules and pustules. He had been using topical Elocon cream daily (mometasone furoate 0.1%) and was diagnosed with steroid-induced rosacea. He was prescribed oral doxycycline, ivermectin cream and brimonidine gel. There was initially an improvement in his symptoms but 6 weeks later he developed a florid, facial inflammatory rash across the bridge of his nose and eyelids. Patch testing to the British Society for Cutaneous Allergy (BSCA) standard, facial and medicaments series, as well as the patient’s own products, showed a positive reaction to Mirvaso gel only (day 2 +, day 4 ++). To complicate matters he developed abnormal liver function tests while on doxycycline and on questioning reported regular use of anabolic steroid and testosterone injections purchased online for bodybuilding purposes. On stopping these his liver tests reassuringly normalized. With avoidance of Mirvaso gel he is now managing his symptoms well. A 45-year-old woman presented to dermatology with erythema on the nose and cheeks, typical for rosacea, and at her request was prescribed Mirvaso gel. One year later she represented with a florid periorbital rash and oedema requiring prednisolone. Occupational ACD linked with her job in a paint mixing factory was initially suspected. Patch testing to the BSCA standard, medicaments and facial series showed a positive reaction on day 4 to brimonidine gel only. Since avoidance her skin has been clear. Individual constituents of the gel were not sent to us after we contacted the manufacturer. We would like to raise awareness that in addition to rebound erythema, topical brimonidine gel is also a cause of severe facial ACD. Patch testing to the patient’s own medicaments should be performed in suspected cases.