Sudden death due to anaphylactic shock in a patient with an intact hepatic hydatid cyst.

Hydatid disease of the liver is a parasitic infection primarily caused by the larvae of Echinococcus granulosus. Hydatid cysts may remain clinically silent for many years and are often an incidental finding on ultrasonography performed for unrelated reasons. Sudden death due to unrecognized hydatid cysts can occur, and rare case reports of this kind are present in the literature. We present a sudden death due to an intact hydatid cyst in a 13-year-old girl, who had a sudden onset of anaphylactic shock after a blunt abdominal trauma. Sudden death in this case was attributed to anaphylactic shock caused by intravascular spread of the cyst contents. We believe that high intracystic pressure coupled with blunt trauma was the cause of leakage of cystic fluid into the bloodstream. In cases of sudden death in endemic areas, the possibility of a hydatid disease should be taken into consideration, especially if no other cause is evident.