Subcutaneous emphysema, defined as the abnormal introduction of air into subcutaneous tissues, is a rare complication of dental treatment. More common causes of this entity include trauma, head and neck surgery, and general anesthesia. We present a case of periorbital subcutaneous emphysema that clinically appeared as unilateral angioedema during a dental treatment.
A 72-year-old woman with a medical history of hypertension and hypothyroidism presented to her dentist for a crown preparation of the left maxillary second molar. She denied any recent medication changes and had no history of urticarial drug reactions. She had a history of chronic periodontal disease, which left her with 4 mm of exposed root and a lack of attached gingiva.
During the dental procedure, 1 carpule of 4% articaine hydrochloride with 1:100 000 epinephrine was injected using a 30-gauge needle at the height of the mucobuccal fold of the left maxillary second molar (local infiltration). Nitrous oxide gas was also administered for 35 minutes at the patient’s request. Knitted retraction cord size No. 0 impregnated with aluminum chloride hexahydrate was placed in the gingival sulcus to retract the buccal mucosa and obtain hemostasis. No air-driven tools were used for shaping the tooth.
In preparation for the final impression, the site was then thoroughly rinsed with a combination of air and water, under equal pressure, using an air-water syringe. Within minutes, the patient developed significant soft-tissue swelling of the left lower eyelid and malar cheek. Vital signs were stable. She did not report any pain, visual problems, or difficulty breathing. The procedure was suspended. Twenty-five milligrams of diphenhydramine was administered for a suspected angioedema, and she was escorted to the emergency department (ED) for further evaluation.
Physical examination in the ED revealed prominent soft-tissue swelling of the left lower eyelid and malar cheek (Figure), and crepitus was noted on palpation. Subcutaneous emphysema was diagnosed. Her symptoms resolved over 5 days without any further complications. The patient’s dental treatment was accomplished several weeks later without incident.
A, This image demonstrates prominent soft-tissue swelling of the left lower eyelid. B, Lateral view of the soft-tissue swelling of the left lower eyelid.
Subcutaneous emphysema is a rare complication of dental treatment that has been reported in the dental literature.1- 5 Dermatologists, emergency care providers, and primary care physicians should be aware of this complication which could be misinterpreted as angioedema as part of an anaphylactic reaction. Tooth extraction, especially the mandibular third molar, is the most commonly reported portal of entry of subcutaneous emphysema. The widespread use of air-driven handpieces has led to an increased risk of iatrogenic subcutaneous emphysema. In this case, no air-driven tools were being used immediately prior to the observation of the reaction. We suspect that the lack of attached gingiva would have allowed air to penetrate under the unattached gingiva during the placement of the retraction cord or during use of the air-water syringe used to maintain dryness and visibility.
Once air enters under the dermal layer, it may remain locally at the surgical site or continue to dissect along the fascial planes. The clinical results are local swelling, tenting of the skin, and crepitation on palpation. In extreme cases, air introduced under high pressure could pass through the masticatory space into the parapharyngeal and retropharyngeal areas, penetrating into the mediastinum. As a result, air embolism is a very rare but serious potential complication.3,4 Patients with subcutaneous emphysema usually recover spontaneously without use of any specific treatment, as was the case with our patient.1
Corresponding Author: Kassie A. Haitz, MD, Section of Dermatology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (Kassiehaitz@gmail.com).
Published Online: June 18, 2014. doi:10.1001/jamadermatol.2014.478.
Conflict of Interest Disclosures: None reported.
Haitz KA, Patel AJ, Baughman RD. Periorbital Subcutaneous Emphysema Mistaken for Unilateral Angioedema During Dental Crown Preparation. JAMA Dermatol. 2014;150(8):907-909. doi:10.1001/jamadermatol.2014.478