Echinococcus granulosis tapeworms' definitive hosts are dogs who live in endemic areas. Humans are infected by petting dogs or eating infected, not propely, heated food. In multiple organs, preferably in liver and lungs, these tapeworms can form cysts which in time might cause mechanical complications. A 7 year old Syrian boy was brought to our emergency department unconsciously after a light abdominal trauma. On ultrasound and CT there was no sign of traumatic injury, but a ruptured echinococcal cyst was found in the liver. The patient developed a severe anaphylaxis, with hypotension and loss of consciousness on the spill of the echinococcal cyst. The cyst was removed surgically and the boy was treated with medication. In patients with unexplained anaphylaxis, from an echinococcus endemic area, rupture of an echinococcal cyst should be part of the differential diagnosis.