Benign subcutaneous emphysema of the upper extremity.

Benign subcutaneous emphysema is a rare clinical entity, documented by only a small collection of case reports. The presence of crepitus on physical examination and subcutaneous gas on radiographs is concerning for necrotizing fasciitis. Necrotizing fasciitis is a dangerous and deadly infection accounting for 500 to 1000 cases annually in the United States, with mortality rates of up to 76%. Delay in surgical treatment is related to increased morbidity and mortality; therefore, a high clinical suspicion should be maintained in patients with subcutaneous emphysema and/or crepitus. It is critical to recognize that no laboratory result or radiologic finding should delay surgical intervention if a high clinical suspicion for necrotizing fasciitis exists. However, not all subcutaneous emphysema represents a life-threatening infection. This article presents a case of benign subcutaneous emphysema treated with close observation and prophylactic antibiotics. Patients with necrotizing fasciitis typically appear ill and have the triad of swelling, erythema, and disproportionate pain. Patients who are not systemically ill and have minimal pain, no significant inflammatory changes at the site of crepitus, and stable hemodynamic parameters can be treated conservatively, with the caveat that close clinical monitoring is essential to avoid the unnecessary morbidity and mortality that can result from delaying intervention in the case of necrotizing fasciitis.