MSFinals-2252

MSFinals-2252

A 16-year-old female presents to the emergency department with peri-umbilical pain. The pain is sharp in nature, is exacerbated by coughing and came on gradually over the past 12 hours. On examination, she is unable to stand on one leg comfortably and experiences pain on hip extension. The is no rebound tenderness or guarding. A urine pregnancy test is negative, and her temperature is 37.4ºC. The following tests are done:

Hb 135 g/L Male: (135-180)
Female: (115 – 160)

Platelets 300 * 109/L (150 – 400)

WBC 14 * 109/L (4.0 – 11.0)

Neuts 11 * 109/L (2.0 – 7.0)

Lymphs 2 * 109/L (1.0 – 3.5)

Mono 0.8 * 109/L (0.2 – 0.8)

Eosin 0.2 * 109/L (0.0 – 0.4)

Na+ 136 mmol/L (135 – 145)

K+ 4 mmol/L (3.5 – 5.0)

Urea 6 mmol/L (2.0 – 7.0)

Creatinine 80 µmol/L (55 – 120)

CRP 24 mg/L (< 5) What is the most likely diagnosis?