Redefining parapharyngeal space infections

Objectives: Our intent was to review the clinical signs, computed tomography (CT) scans, treatment, and outcome of parapharyngeal space infections (PPIs), and to define 2 types of infections of the parapharyngeal space (PPS) according to the location of the infectious process. Methods: We performed a retrospective analysis of patients hospitalized in a tertiary university hospital with a diagnosis of PPI, abscess, or deep neck abscess between 1988 and 2004. Files and CT scans were reviewed after classification into 2 groups: 1) infection located in the posterior part of the PPS (PostPPI); and 2) infection located in the anterior part of the PPS (AntPPI). Results: Twenty-two patients had a PostPPI; their ages ranged from 10 months to 24 years. Five patients underwent surgical drainage, and 17 others were treated solely with intravenous antibiotic therapy. No pus was found during surgery in 2 patients. The average time of hospitalization was 10 days. Only 1 complication (aspiration pneumonia) was observed. Seven patients had an AntPPI; their ages ranged from 1.5 years to 65 years. All patients underwent surgical drainage, and pus was detected in all cases. The average time of hospitalization was 35 days. Complications (septic shock, respiratory arrest, mediastinitis, pleural empyema, pericarditis) were observed in 4 patients. Conclusions: The term "parapharyngeal abscess" was assigned long before the CT scan era, and was based on physical examination and plain film radiology. In essence, the entity PPS "abscess" or "infection" is composed of 2 different disorders. Infection located in the posterior part of the PPS with no invasion into the parapharyngeal fat and with no extension into other cervical spaces except the adjacent retropharyngeal space may be termed posterior parapharyngeal infection or parapharyngeal lymphadenitis. This is a relatively benign condition, and nonsurgical treatment should be considered. Infection involving the parapharyngeal fat may be termed parapharyngeal abscess or deep neck abscess. Diffusion into the mediastinum and other severe complications are frequent. Urgent surgical drainage is therefore mandatory.