Anaphylaxis to Hippobosca equina (louse fly)

Abstract

IgE-mediated allergy to insects different from Hymenoptera species is seldom reported. To describe and study the case of a previously nonatopic man with an anaphylactic reaction (grade III, Müeller) caused by a bite from a louse fly (Hippobosca equina). In vivo (skin prick tests) and in vitro (enzyme-linked immunosorbent assay and sodium dodecyl sulfatepolyacrylamide gel electrophoresis immunoblotting) tests were used for diagnosis. Cross-reactivity between H. equina and different insects was investigated. Results of skin prick tests and serum specific IgE were positive to H. equina. Immunoblot inhibition studies identified common bands in H. equina, Apis mellífera, and Musca domestica, but this cross-reactivity did not affect a band of 16 or 15 kDa. This molecular weight is similar to that of phospholipase A2 in A mellifera venom. We describe a case of IgE-mediated allergy to H. equina in which specific molecular band proteins seemed to be responsible for the reaction.