To the Editor.—
We have read with great interest the article by Wong et al1 concerning idiopathic anaphylaxis. We would like to add some comments regarding the diagnostic approach.Echinococcosis (hydatid disease) is an endemic parasitic infection in Mediterranean regions, the Middle East, Australia, and South America. Cases reported from the USA have occurred in immigrants. It is well known that systemic anaphylaxis may be the sole manifestation of complete or incomplete rupture of hydatid cyst.2-7 These cases would be considered as "idiopathic" if complementary studies directed to rule out echinococcal infestation were not performed. Hence, we suggest that all serologic and radiologic procedures to exclude or confirm hydatic disease should be requested during the differential diagnosis of systemic anaphylaxis.