What is an expected physical finding in a child with a kidney infection?

Flank pain is a common and expected physical finding in a child with a kidney infection, also known as pyelonephritis. This pain typically occurs in the lower back on the side of the affected kidney. In children, a kidney infection may cause inflammation and irritation in the renal tissue, leading to discomfort that can be felt in the flank area.

While abdominal pain may sometimes accompany a kidney infection, it is not as specific or characteristic as flank pain. Chest pain is not associated with kidney infections and could suggest a different type of condition, such as a respiratory issue. Likewise, headaches, while they can occur for various reasons, are not a direct indication of a kidney infection. The presence of flank pain in the context of other symptoms such as fever, urinary urgency, and possibly nausea strongly suggests the presence of a kidney infection in children, making it the correct expected physical finding in this scenario.