A child complains of leg pain that has been persistent for two weeks. What should be considered in the differential diagnosis?

In evaluating a child with persistent leg pain, acute lymphocytic leukemia (ALL) is a serious condition that should be considered in the differential diagnosis due to the specific characteristics associated with the disease. ALL can cause varied symptoms, including bone pain, which might be severe and persistent, often accompanied by other systemic signs such as fatigue, pallor, easy bruising, or infections, indicating the child's overall health status is affected. The nature of the pain in leukemia can be related to bone marrow infiltration and immune system compromise, which is quite different from other causes of leg pain in children.

In contrast, while Osgood-Schlatter disease and growing pains are common conditions that could also cause leg discomfort, they typically present differently and usually do not have the same degree of severity or systemic involvement as seen in leukemia. Psychogenic pain may occur, but it generally would not be the primary concern in this situation without other indicators pointing toward a psychological origin. Therefore, in a case of persistent leg pain, especially one that does not respond to usual analgesics or rest, considering ALL is crucial to rule out a potentially life-threatening condition.