Clinical classification of peritonsillar abscess based on CT and indications for immediate abscess tonsillectomy.

OBJECTIVE: To clarify indications for immediate abscess tonsillectomy (IAT) for peritonsillar abscess (PTA). METHODS: A retrospective study was performed on 99 patients who were diagnosed with PTA on the basis of computed tomography (CT). Based on CT findings, PTA patients were classified into two categories by abscess shape: Oval type and Cap type. Furthermore, abscess location was differentiated into superior and inferior, resulting in a final classification of 4 categories: superior Oval type; superior Cap type; inferior Oval type; and inferior Cap type. In addition, the proportion of PTA patients showing extraperitonsillar spread into parapharyngeal spaces in each category was examined. RESULTS: Superior Oval-type PTA was the most common. Thirteen patients showed extraperitonsillar spread. When CT classifications were compared with clinical findings, patients with inferior Cap-type abscess displayed extraperitonsillar spread more frequently than the other categories of PTA. In all 13 patients, the parapharyngeal space was involved. In addition, 3 patients displayed retropharyngeal space involvement. In all 13 cases, abscess remained above the hyoid bone. CONCLUSIONS: Inferior Cap-type PTA may need more intensive and reliable treatment, such as IAT, which might be effective for PTA showing extraperitonsillar spread.

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.