Anaphylaxis to carrageenan: a pseudo-latex allergy

Anaphylactic reactions during a barium enema have been attributed to allergy to latex on the barium enema device. The observation of anaphylaxis during barium enema without latex exposure or latex allergy led to the performance of an allergy skin test to the barium enema solution.

Individual components of the barium enema solution were obtained for double-blind skin testing. A RAST to identify specific IgE antibodies to the skin test active agent was established.

Carrageenan, a component of the barium enema solution, produced positive reactions to allergy skin test and RAST. Gastrointestinal symptoms for which the patient was being investigated by the barium enema subsequently disappeared with a diet free of carrageenan.

Carrageenan is a previously unreported cause of anaphylaxis during barium enema. It is an allergen widely distributed in common foods and potentially could account for some symptoms related to milk products or baby formula.