A curious case of idiopathic subcutaneous emphysema.

Subcutaneous emphysema presents as a painless swelling of the tissues because of air tracking along tissue planes. Risk factors include trauma, pneumothorax, retching, severe cough and dental or endoscopic procedures. While most cases resolve spontaneously once the cause is treated, severe cases with compartment syndrome and hemodynamic instability may require surgical decompression. Herein, we present a case of idiopathic subcutaneous emphysema that resolved spontaneously.

A 44-year-old woman with a history of Behçet’s disease and fibromyalgia has presented with swelling in the neck and face for 4 days. She was diagnosed with Behçet’s disease about 25 years ago and has tried several therapies including azathioprine, cyclophosphamide, methotrexate and adalimumab. She had a subclavian central venous port for more than a year, which was placed for administration of immunotherapy. Chest X-ray demonstrated subcutaneous emphysema of the neck (Fig. 1A). She denied having any trauma, vomiting, fever, recent dental procedures and smoking or recreational drug use. Oral examination was negative for perforated ulcers or dental abscess, and ENT exam was unremarkable. CT scan of the chest excluded pneumomediastinum and any pulmonary pathology that could result in subcutaneous emphysema (Fig. 1B and C). Bronchoscopy was unrevealing. The patient had spontaneous resolution of symptoms over the next few days. One possible explanation is that the air was sucked in through the insertion site of subclavian port due to negative intrathoracic pressure being transmitted to the perivascular interstitial space [1]. However, we did not remove the port as the emphysema resolved and the association was just an assumption. Behcet’s disease may predispose patients to develop subcutaneous emphysema. While more data are needed to determine whether a causal relationship exists, this is an observation based on ours and two previously reported cases [2, 3].

Figure 1:

(A) Chest X-ray demonstrating bilateral neck subcutaneous emphysema seen as radiolucent streaks throughout the subcutaneous tissue (arrows). Line arrow points to the subclavian port. (B and C) CT scan of the chest demonstrating diffuse subcutaneous emphysema over the neck and anterior chest (arrows). There was no evidence for pneumomediastinum or pneumothorax