B. Anibarro et Jl. Fontela, IMMEDIATE RHINOCONJUNCTIVITIS INDUCED BY METAMIZOLE AND METRONIDAZOLE, Annals of allergy, asthma, & immunology, 78(4), 1997, pp. 345-346
Objective: To report a case of immediate rhinoconjunctivitis induced b
y both metamizole and metronidazole. Methods: Skin-tests (prick and in
tradermal) were performed with metamizole, metronidazole, and espyrami
cine. Standard PAST was carried out with metamizole and metronidazole.
Oral challenge tests were performed single blind with Rhodogil, metro
nidazole, espyramicine, metamizole, aspirin, and propyfenazone. Result
s: Both skin tests and PAST were negative. We also found that the pati
ent tolerated therapeutic doses of espyramicine, aspirin, and propyfen
azone. Challenges with Rhodogil, metamizole, and metronidazole elicite
d immediate rhinoconjunctivitis. Conclusion: This is an exceptional ca
se of immediate rhinoconjunctivitis induced by two unrelated drugs (me
tamizole and metronidazole). The pathogenic mechanism implicated in th
is process remains unclear. Inhibition of the cyclooxygenase pathway w
as excluded and we could not demonstrate the presence of specific IgE
antibodies. Nevertheless, an immunologic or idiosyncratic mechanism co
uld be responsible.