Several infectious processes of intra-abdominal origin may atypically present as skin or soft tissue infections or abscess in the thigh.Case ReportWe describe the case of a 73-year-old woman who presented to the emergency department with the clinical picture of a skin infection of the right leg. The patient's condition deteriorated during medical treatment with intravenous antibiotics. Subsequent radiologic imaging revealed that the complaints were caused by a bulging retroperitoneal appendicular abscess along the iliopsoas muscle, although the patient experienced no abdominal symptoms. The patient recovered completely after surgical intervention.Why Should An Emergency Physician Be Aware of This?Timely performance of anatomic imaging in patients with unexplained skin or soft tissue infections and thigh abscesses is important because these findings may be manifestations of an abdominal pathology. A correct diagnosis in the emergency department prohibits delays in treatment.