Renewal of peritonsillar abscess: Impact of the bacterial species of the infection and clinical features of the patient-A prospective comparative aetiological study.

OBJECTIVES: To compare the bacterial species and patient clinical features in peritonsillar abscesses between patients who had renewal (renewal group) and those who did not (recovery group). DESIGN: Prospective comparative aetiological study. SETTING: Tertiary referral centre. PARTICIPANTS: A total of 180 adult peritonsillar abscess patients were prospectively enrolled and treated as outpatients with incision and drainage and oral antibiotics. Bacteria from the pus were evaluated with a microarray assay. All contact with the healthcare system and renewal of the symptoms were recorded. MAIN OUTCOME MEASURES: Different bacterial species and patient clinical features between the renewal and recovery groups. RESULTS: Of the 180 enrolled patients, 18 experienced a renewal of symptoms. Bacteria from the Streptococcus anginosus group were detected in the patient samples of the renewal group more often than in those of the recovery group (P=.002). No isolated Streptococcus pyogenes samples were reported in the renewal group, while in the recovery group it was reported on 24% of the patients (P=.014). In the renewal group, patients over age 40 experienced symptom renewal faster than the younger patients (P=.013) and were more likely to be male (P=.036). CONCLUSIONS: Bacteria in the Streptococcus anginosus group appear to predict renewal of PTA symptoms, while Streptococcus pyogenes was not found in our patients with symptom renewal. Certain subgroups of patients should be followed more closely.