Benzalkonium Chloride in Eye Drops Causing Allergic Contact Dermatitis: A Case Series.

We present three patients who developed allergic contact dermatitis (ACD) from benzalkonium chloride (BAK) in ophthalmic drops. BAK is a preservative commonly found in ophthalmic formulations and there is a rising trend of ACD to this allergen. The irritant and sensitising properties of BAK on the ocular mucosa will be discussed. This paper will also explore BAK allergy from eye drops in patients with atopic dermatitis and those using dupilumab.