Ethylenediamine tetraacetate is a widely used preservative, especially in ophthalmic solutions. It was found to be the cause of an acute allergic conjunctivitis and periorbital dermatitis. Subsequent testing revealed two additional cases of delayed hypersensitivity to this compound.
Two of the three cases cross-reacted to ethylenediamine, a structurally related compound. Recommendation for patch testing with 1% concentration in water or petrolatum is made. The increasing problem of reactions to preservatives is discussed.
Raymond JZ, Gross PR. EDTA: Preservative Dermatitis. Arch Dermatol. 1969;100(4):436-440. doi:10.1001/archderm.1969.01610280054008