The Case Files (2013)

A 31-year-old woman presented to the emergency department with facial swelling and pain secondary to a dog bite that occurred earlier in the day. Immediately after the bite had occurred, she reported cleaning her face with tap water, blowing her nose, and applying antibacterial ointment. She reported that the swelling had developed rapidly as had a “crunching” sensation under her skin that seemed to spread to her neck. She denied fever, chills, nausea, vomiting, diarrhea, discharge from facial wounds, difficulty moving her eyes, or changes in vision. The patient's vital signs were stable and within normal limits. Physical exam revealed a tearful, uncomfortable-appearing woman with pronounced left-sided facial swelling extending from the periorbital region to her upper lateral neck that was associated with erythema, tenderness, and palpable crepitus. No induration or fluctuance was noted. Two puncture wounds were visible, the first near the medial portion of the malar pad and the second lateral to the nasofacial crease near the ala. Both wounds were without active bleeding or discharge. The patient was able to open her eyes spontaneously, her pupils were equal, round, reactive to light, and her extraoccular muscles were intact. The remainder of her physical exam was normal. Percocet was given for pain control. Blood work was drawn, and a CT of the orbits with contrast was obtained. The labs were unremarkable except for mild leukocytosis of 12.9x103μL without bandemia. Chest x-ray was normal. The CT of the orbits revealed a large amount of air within the subcutaneous tissues in the left periorbital region in the pre- and postseptal regions and in her left cheek with extension into the deep soft tissues of the neck. The subcutaneous emphysema extended around the left masticator space and into the prevertebral soft tissues. No discrete focal fluid collection was appreciated, but the radiologist could not exclude necrotizing fasciitis. The patient was admitted to the hospital, and had infectious disease, plastic surgery, ENT, and ophthalmology consultations. She was treated with IV ampicillin/sulbactam and clindamycin, topical mupirocin, and gatifloxacin eye drops. The patient later recalled that she first noted the rapid cheek and eye swelling after forcefully blowing her nose. She also reported that it had remained remarkably unchanged since onset. This information, in addition to the location of the puncture wound and the nontoxic presentation of the patient, makes it plausible that the bite facilitated the inflation of the tissues, rather than an extension of the facial cellulitis. The patient's leukocytosis resolved within 12 hours, her blood cultures remained negative for five days, and all other labs continued to be unremarkable. The patient improved significantly after four days, and was discharged home for outpatient follow-up with plastic surgery. Ultimately, no surgical intervention was required, and the patient resolved clinically without lasting cosmetic effects.Periorbital swelling around patient's left eye and puncture wounds to the left of nose.Sagittal view of CT orbits with contrast showing preseptal (solid arrows) and postseptal air (dashed arrows).Subcutaneous emphysema is the result of either the presence of a gas-producing organism beneath the skin or the effect of air that has been physically forced into tissues. The latter generally has a benign course, but the former may result in a necrotizing skin infection with considerable morbidity and mortality. The patient may present in both cases with palpable crepitus, tenderness, and swelling. The subcutaneous air may be tracked along the various surrounding fascial planes, creating potentially dramatic imaging in an otherwise healthy patient. Prior literature describes the known but rare phenomenon of iatrogenic subcutaneous emphysema in the face generally following the use of air-driven dental handpieces or endotracheal intubation in which air is forcibly introduced into the tissues. (J Oral Maxillofac Surg 2009;67[6]:1265.) Also recorded is the introduction of air into the facial tissues from tears in the tracheal mucosa following intense coughing or vomiting. (J Oral Maxillofac Surg 2009;67[6]:1265.) Rarely, serious complications may arise in which the air from the facial tissues may travel down to the pericardial space and lead to significant cardiac compromise, or alternatively may travel upward and lead to ischemic lesions in the brain. (Anesth Analg 2008;106[1]:249.) Generally, however, isolated cases of subcutaneous emphysema resolve spontaneously over a week, and require no intervention. Necrotizing fasciitis in contrast has a considerably more destructive course. It was first described in 500 BC by Hippocrates as “erysipelas all over the body when the exciting cause was a trivial accident” that led to the “flesh, sinews and bones [falling] away in large quantities,” and caused “many deaths.” (Lancet 1994;344[8921]:556.) Little has changed today, and the initial presentation of necrotizing fasciitis can appear largely innocuous, usually originating from a minor wound and being accompanied by nonspecific findings. It can, however, lead to extremely significant morbidity and mortality. (Ann Surg 1995;221[5]:558.) Recent studies have shown that decreased mortality is directly correlated with early diagnosis and subsequent early treatment. (Am Surg 1998;64[5]:397.) Despite improved diagnostic imaging and considerable treatment advances, the mortality rate of necrotizing fasciitis has held steady at 25-30 percent for the past 30 years. (Arch Surg 2005;140[2]:151.) This case differs from an isolated instance of subcutaneous emphysema and a serious necrotizing skin infection because the preceding trauma led to the presence of an overlying cellulitis as well as a breach in the skin, which later provided a well-positioned portal of entry for air exiting the nose. This case resulted in a desirable outcome with minimal intervention, but it cannot be overstated how important it is to remain vigilant and aggressive when evaluating soft tissue infections. The presentation of a nontoxic patient with extensive subcutaneous emphysema, overlying cellulitis, and an infection-prone mechanism of injury must raise suspicion for an early necrotizing skin infection.Transverse view of CT orbits with contrast showing subcutaneous air in left cheek (arrows) and prevertebral space (*).Coronal view of CT orbits with contrast showing subcutaneous air in the masticator space (*) and neck (arrow).