Clinical Mimics: An Emergency Medicine-Focused Review of Cellulitis Mimics

Background Cellulitis is a common clinical condition with low rates of morbidity and mortality if treated appropriately. Mimics of cellulitis presenting with erythema, edema, warmth, and pain can be associated with grave morbidity and mortality if misdiagnosed. Objective This review investigates the signs and symptoms of cellulitis, mimics of cellulitis, and an approach to the management of both cellulitis and its mimics. Discussion The current emergency medicine definition of cellulitis includes erythema, induration, warmth, and swelling. Given the common pathophysiologic pathways, cellulitis mimics often present in an analogous manner. These conditions include septic bursitis, septic joint, deep vein thrombosis, phlegmasia cerulea dolens, necrotizing fasciitis, flexor tenosynovitis, fight bite (closed fist injury), orbital cellulitis, toxic shock syndrome, erysipelas, abscess, felon, paronychia, and gouty arthritis. Many of these diseases have high morbidity and mortality if missed by the emergency physician. Differentiating these mimics from cellulitis can be difficult in the fast-paced emergency setting. A combination of history, physical examination, and focused diagnostic assessment may assist in correctly identifying the underlying etiology. For many of the high mortality cellulitis mimics, surgical intervention is necessary. Conclusion Cellulitis and its mimics present similarly due to the same physiologic responses to skin and soft tissue infections. A combination of history, physical examination, and diagnostic assessment will help the emergency physician differentiate cellulitis from mimics. Surgical intervention is frequently needed for high morbidity and mortality mimics.