MSFinals-4682
A 10-year-old girl presents to the Emergency Department with her mother, complaining of right iliac fossa pain for the past 2 days. She has no significant medical history, except for a recent cold and sore throat. She has had a high fever for the past 2 days and has lost her appetite, but denies any other symptoms. On examination, her temperature is 38.9 °C and her heart rate is 130 bpm. She has palpable and slightly tender submandibular and cervical lymph nodes on both sides. Her chest is clear, with transmitted sounds from the upper airways. Abdominal examination reveals marked tenderness in the right iliac fossa without guarding. A urine dipstick shows 2+ ketones and 1+ protein. Her FBC results are as follows: haemoglobin 145 g/l (normal range 135–175 g/l), WCC 14.3 × 109/l (normal range 4–11 × 109/l), and platelets 425 × 109/l (normal range 150–400 × 109/l). What is the most likely clinical diagnosis?