Mimics of Lower Extremity Cellulitis: An Approach to the Red Leg.

Cellulitis is a common clinical diagnosis; however, studies have demonstrated a surprisingly high misdiagnosis rate: approximately 30% of cases of presumed cellulitis actually have a non-infectious diagnosis. This high rate of misdiagnosis contributes up to $515 million in avoidable health care spending in the United States each year. There is a broad differential diagnosis for patients presenting with presumed lower extremity cellulitis, which includes inflammatory and noninflammatory conditions of the skin. Accurate diagnosis is crucial to management. When patients present with a "red leg," it is important that the treating team evaluates the history and clinical findings thoroughly.