Anaphylactic reaction after ingestion of small doses of morphine and codeine: evidence for an IgE-mediated reaction

We report the case of a 37 years-old nonatopic woman who experienced several anaphylactic reactions after ingesting low doses of the methylmorphine derivatives codeine and codethyline. The IgE mediated mechanism was confirmed by the detection of morphine-specific IgE antibody, determined by radioimmunoassay (RAST). Cross reactivity with codeine was shown by inhibition of the morphine RAST. The gravity of the clinical state not permitting an oral provocation test, we were able to confirm an IgE-mediated mechanism by demonstrating that the anti-morphine IgE did not recognize the quarternary ammonium group. [Copyright &y& Elsevier]