Background Due to current human migratory patterns, emergency physicians in developed countries are facing emergent clinical presentations of neglected tropical diseases with increasing frequency. In those situations, the clinician's diagnosis is often delayed due to a lack of familiarity with the disease. Case Report We present the case of a 25-year-old Peruvian man who presented to the Emergency Department complaining of dyspnea and abdominal pain after upper abdominal trauma. His physical examination revealed mouth and eyelid edema in association with epigastric pain. An abdominal computed tomography scan revealed a liver hydatid cyst. Emergent surgical evacuation of the cyst was required to control the anaphylactic reaction. Why Should an Emergency Physician Be Aware of This? Anaphylaxis in the setting of a complicated hydatid cyst is a life-threatening disease. Critical care management and emergent surgical evacuation of the cyst are indicated.