Allergy to Ophthalmic Preservatives

Jison Hong; Leonard Bielory


Curr Opin Allergy Clin Immunol. 2009;9(5):447-453. 

In This Article


Parabens are esters of p-hydroxybenzoic acid. They act by targeting molds and fungi rather than bacteria. In an assessment of preservative sensitivity in the United Kingdom, the results of patch testing using the extended British Contact Dermatitis Society Standard series, they found that parabens mix has the highest irritancy rate.[29]

Animal Studies

Becquet et al.[7] showed alteration of the rat conjunctival surface after 1 month of treatment with instillation of eye drops containing 0.05% methyl parahydroxybenzoate with increased number of epithelial cell layers, loss of goblet cells, and appearance of keratinization of the most superficial cell layers.

Human Studies

There are few human studies performed recently because of their well established role in delayed hypersensitivity. Nagel et al.[30] presents a case report of bronchospasm and pruritus when a hydrocortisone preparation containing methylparaben and propylparaben is given intravenously to an asthmatic patient. Administration of the hydrocortisone preparation without the paraben preservative did not elicit the same response. Skin tests for immediate hypersensitivity to parabens were positive. They were able to conclude that parabens are capable of producing immunologically mediated, immediate systemic hypersensitivity reactions. Henry et al.[31] also describes the relationship of parabens and the development of contact urticaria.