Allergic Contact Dermatitis to a Nasal Cannula

To the Editor.—  Uncured epoxy resins have been a common cause of occupational contact dermatitis. Plastic medical equipment and consumer products, however, often also contain varying amounts of epoxy resins. Epoxy plasticizers and stabilizers are most frequently used in polyvinyl chloride systems, but are also used in synthetic rubbers and other plastic polymers.¹ It is the nonhardened, uncured form of epoxy resin that is thought to be allergenic. Hardened epoxy resin is not allergenic.² Incompletely hardened epoxy resins still appear in plastic medical equipment, such as certain nasal oxygen cannulas.The patient presented clearly demonstrates sensitivity to the epoxy oil component of her nasal cannula in that she had a positive patch test result to her cannula and to epoxy resin. Chemical analysis³ of the cannula revealed presence of bisphenol A-type epoxy resin. There has been only one previous report of oxygen nasal cannula sensitivity, by Wright