Methods: Subjects with hypersensitivity reactions to any arylpropionic acid derivatives were included in the study. A DPT was carried out to rule out cross-intolerance (non allergic hypersensitivity). Drug imputability was confirmed by DPT when after drug intake repetitive well defined episodes were reported. Serum tryptase was quantized by immunoassay and in the affected skin by immunohistochemistry and urine N-methyl histamine by immunoassay.
Results: A total of 42 cases were classified as selective immediate responders. Ibuprofen was the drug most frequently involved, followed by naproxen and desketoprofen. Quantitation of tryptase levels in peripheral blood and skin biopsies and N-methyl histamine in urine were indicative of an IgE immediate selective response.
Conclusions: Arylpropionic acid derivatives are responsible for immediate allergic selective responses. Further studies are in progress for identifiyng the possible adducts (hapten-carrier complexes) implicated and the existence of cross-reactivity.