Int J Emerg Med (2010) 3:427–429 DOI 10.1007/s12245-010-0189-5 CASE REPORT Dentist’s drill allergy? David Sainsbury & Thiagarajan Jaiganesh Received: 30 August 2009 / Accepted: 20 April 2010 / Published online: 13 July 2010 # Springer-Verlag London Ltd 2010 Abstract Subcutaneous emphysema of the face and neck can develop following restorative dentistry, particularly when air turbine drills are used. We present a case in which the dentist mistook the subcutaneous emphysema following such a procedure for an allergic/anaphylactic reaction and sent him to the emergency department in an ambulance. The differential diagnosis and the subsequent management, including the role of oxygen and techniques to prevent such complications, are discussed. Keywords Subcutaneous emphysema . Dental air turbine drill A 40-year-old man developed a swelling to his left side of his face during the course of a root canal treatment. He was undergoing some dental restoration of his left upper second molar. During the cavity preparation, the dentist noticed some swelling over the left parotid area that slowly started to spread to the left cheek and lower eyelid. The root canal treatment was stopped, and the patient was referred to our emergency department as an allergic reaction/anaphylactic reaction by his dentist in an ambulance. Examination revealed a swollen left half of his face (Fig. 1) with crepitus on palpation. There was no trismus. There was no increase D. Sainsbury Mayday University Hospital, London Road, Croydon, Surrey CR7 7YE, UK e-mail: David.sainsbury@mayday.nhs.uk T. Jaiganesh (*) St Georges Hospital, Blackshaw Road, Tooting SW17 0QT, UK e-mail: jaiganesh@doctors.org.uk in the size of the swelling during his stay in the department. There was no dysphagia. The vital signs were normal, and he was apyrexial. The cardiovascular and respiratory system examination was normal. The sudden onset of head and neck swelling after a dental procedure made us draw up a list of differential diagnoses that included haematoma, cellulitis, allergic reaction, angioedema and subcutaneous emphysema. However, we managed to exclude the others one by one on clinical examination, haematological, biochemical and radiological investigation. Haematoma was unlikely as there was no active bleeding during the procedure or after the procedure. There was no tenderness on palpation, no visible haematoma on intra- or extra-oral examination, no history of clotting abnormalities, and his clotting studies were normal. Cellulitis was unlikely as there were no local signs of inflammation such as warmth, redness, tenderness or raised temperature. The white cell count and the C-reactive protein were normal as well. The swelling was localised to the left half of the face and neck with no other rash or swelling elsewhere. The patient was not known to be allergic to any substances and had undergone previous root canal procedures under the same dentist. This ruled out an allergic reaction. Furthermore, intraoral examination did not reveal any swelling to the tongue or the uvula or lips, etc. There was no family history of allergy or angioedema. He was not on any medications that could have caused angioedema. Furthermore, angioe- dema swelling does not produce palpable crepitus. This ruled out an angioedema. There was palpable crepitus felt over the swelling on clinical examination. Given that an air turbine dentist drill was used, a diagnosis of subcutaneous cervico-facial emphysema was made. The subcutaneous emphysema was confirmed on facial x-rays (Fig. 2). A chest x-ray was also performed to rule out the presence of a pneumomediastinum (Fig. 3). The patient was admitted to our Clinical Observation Unit and was provided with high-