A 61-year-old Caucasian woman, diagnosed 13 years previously, by transbronchial lung biopsy, with IPF. The patient had been treated with corticosteroids up to two years earlier. She had been receiving continuous home oxygen therapy for 20 months. Six years earlier she had been diagnosed with duodenal ulcus and had no other history of interest.
In the week prior to her admission she presented with frequent and severe coughing attacks, without expectoration, fever or increase in her usual dyspnoea. On the day of admission, she presented to the emergency department with sudden swelling in the left cervical region, intermittent central thoracic pain, which increased with coughing and respiratory movements, and dyspnoea at rest.
Physical examination revealed tachypnoea (32 breaths/minute), tachycardia (120 beats/minute), swelling and crackles in the left cervical region, fine crackles in both lung fields and crackles on cardiac auscultation (Hamman's sign), with no paradoxical pulse.
The most relevant analytical data were: leucocytes 23.9x109/l (80% neutrophils), haemoglobin 132 g/l, haematocrit 39.4%, LDH 342 U/l and creatine kinase 123 U/l. Baseline arterial blood gas values were: pH 7.47, PO2 54 torr, PCO2 36 torr, HCO3- 27.1 mmol/l and oxygen saturation 90%. Electrocardiogram showed sinus rhythm at 120 beats per minute, the rest of the tracing being normal. A neck X-ray showed cervical emphysema predominantly on the left. A chest X-ray revealed a bilateral pulmonary fibrosis pattern more marked in the lower fields, with an anterior pneumomediastinum evident in the lateral projection. A computed tomography (CT) scan of the chest showed a marked pattern of bilateral pulmonary fibrosis, a pneumomediastinum and large air bullae in the left upper lobe, with no evidence of pneumothorax.

The evolution was favourable with symptomatic treatment, with subcutaneous emphysema and pneumomediastinum disappearing after 14 days in radiological controls.