RESUMEN
Hydatid disease is a parasitic infection caused by Echinococcus granulosus characterised by cyst formation in any organ, although the liver is the most commonly involved. Hydatid cysts can rupture either spontaneously or following trauma. Surgical treatment can be life-saving. This paper reports the atypical presentation of a young girl admitted to the emergency department. She presented with pain on her palms due to falling down a few steps. Because of the rebound tenderness on the right upper quadrant of her abdomen on physical examination, bedside ultrasonography was performed to identify the underlying cause, and promptly revealed a 62 x 72 mm lobular cyst on the right lobe of the liver with free fluid in the subcapsular area. Shortly afterwards, urticaria developed. Fluid resuscitation, methylprednisolone and diphenylhydramine were administered intravenously. Afterwards she was taken to the operation room for unroofing, drainage and capitonage. In conclusion, primary care and emergency physicians should perform a complete physical examination on all admitted patients with vague symptoms and a high index of suspicion for a ruptured hydatid cyst, even following trivial trauma, especially in endemic regions.