Background Although Hydatid liver disease may be asymptomatic, one complication of Hydatid disease is perforation of the cyst into the peritoneal cavity after trauma. We present herein a case presented after trauma and had a diagnosis of Hydatid cyst rupture into the peritoneum previously asymptomatic boy.

Case A 7-year-old boy presented with mild abdominal pain for 6 h. His parents told that his abdominal pain was suddenly commenced after falling down from swing when playing at the playground. They also complained of itching on the whole body starting soon after the trauma. His blood pressure was 90/60 mmHg, heart rate 118/min, and temperature 37.0°C. On the physical examination, urticaria was seen over the thigh and trunk, abdominal examination revealed generalised tenderness. Ultrasonography and computed tomography showed multiple cystic lesions in the liver and one of them had hypoechoic contents and floating echogenic membranesand also free fluid were seen in the pelvis. Intravenous fluids were started followed Hydrocortisone and antihistamine administered along with antibiotic prophylaxis. The patient underwent surgery, 3 cysts at different localization and also a ruptured cyst 4 cm in diameter at the segment 1 were seen. The germinative membranes and the daughter vesicles were removed and abdomen was irrigated with hypertonic saline (3% NaCl). Postoperative albendazole therapy was given for two months.

Conclusion Rupture of Hydatid cyst should be considered in the differential diagnosis at the presentation of acute abdominal findings with urticaria after abdominal blunt trauma. US and CT are effective in diagnosing of this rare condition.