A 15-year-old girl with fever and abdominal pain.

We present a case of a previously healthy 15-year-old girl with fever, right lower quadrant pain, and hip pain. Her history was notable for a recent laparoscopic appendectomy that was complicated by the development of intraabdominal abscesses. She reported normal bowel movements and good appetite on a regular diet, although she did endorse a recent 5-kg weight loss. Further investigation and examination revealed a diagnosis of Crohn's disease with recurrent psoas muscle abscess as the etiology of her pain and fevers. Psoas abscess is a rare complication of Crohn's disease, and vague presenting symptoms may complicate its diagnosis. This case demonstrates the importance of maintaining a broad differential diagnosis when treating a child presenting with abdominal pain and fever.