Hypersensitivity Reactions to Vaccine Components

Noushin Heidary; David E. Cohen


Dermatitis. 2005;16(3):115-120. 

In This Article


2-Phenoxyethanol (2-PE) is a preservative in some vaccines and is effective against a broad spectrum of microorganisms but particularly against Pseudomonas aeruginosa.[26] The action of 2-PE on gram-negative bacteria is reported to involve the disruption of cell membranes and the uncoupling of oxidative phosphorylation.[27] Since 1970, 2-PE has increasingly been added to cosmetics and pharmaceuticals, including vaccines.[28] Sensitivity to 2-PE is detected by patch testing with 2-PE alone or with Euxyl K400, a biocide that consists of 2-phenoxyethanol and methyldibromoglutaronitrile (MDGN) in a ratio of 4:1. 2-Phenoxyethanol rarely causes sensitization, so the majority of allergic contact dermatitis reactions to Euxyl K400 are due to the MDGN component.[29]

Generalized contact eczema due to 2-phenoxyethanol has been described in a single case report. In the United States, an 18-month-old boy with a strong family history of atopic dermatitis and immediate-type allergy developed generalized eczema twice, both times within 24 hours of routine administration of DTP vaccine.[30] Patch testing with the whole vaccine, as well as with its individual components in standardized concentrations and vehicles, was performed on the skin after resolution of the reaction. The patch-test result with 2-PE (2% in petrolatum) was positive. Substitution of 2-PE with thimerosal in a subsequent DTP booster resulted in no cutaneous adverse events.


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