Empyema Necessitans Diagnosed by Point-of-Care Ultrasound

Empyema necessitans is a rare complication of pleural empyema characterized by the dissection of pus through the soft tissues of the chest wall and eventually through the skin. The skin manifestation may appear as a superficial abscess.

A 63-year-old woman presented to the Emergency Department (ED) with a chief complaint of dyspnea, dry cough, and a cutaneous nodule on her right chest wall. Three weeks prior to her ED visit, she underwent an exploratory thoracotomy and chest tube placement. The chest tube was removed 2 weeks later. Her physical examination was significant for decreased breath sounds over her right lung fields and a painful, fluctuant, and erythematous nodule on the right chest wall where the chest tube had previously been inserted. Externally, the dermal findings appeared to be a superficial abscess. A chest X-ray study showed a large pleural effusion in her right hemithorax. Point-of-care ultrasound (POCUS) performed by an emergency physician showed evidence of a tract extending from the nodule toward the pleural space that led to the correct diagnosis and treatment of empyema necessitans. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is important to distinguish between a superficial abscess, which requires local drainage, and empyema necessitans, which requires either chest tube drainage, open drainage, or even decortication in specific cases. In such cases, POCUS can facilitate a rapid, accurate diagnosis, and lead to the correct treatment.