Evaluation of the acutely limping child.

A limp may be defined as any asymmetric deviation from a normal gait pattern. The differential diagnosis of a limp includes trauma, infection, neoplasia and inflammatory, congenital, neuromuscular or developmental disorders. Initially, a broad differential diagnosis should be considered to avoid overlooking less common conditions such as diskitis or psoas abscess. In any patient with a complaint of knee or thigh pain, an underlying hip condition should be considered. The patient's age can further narrow the differential diagnosis, because certain disease entities are age-specific. Vigilance is warranted in conditions requiring emergent treatment such as septic hip. The challenge to the family physician is to identify the cause of the limp and determine if further observation or immediate diagnostic work-up is indicated.