Predictors of Treatment Failure in the Surgical Management of Peritonsillar Abscesses

Objectives: Peritonsillar abscess (PTA) is the most common deep neck infection and is usually managed with antibiotic therapy and surgical drainage. However, drainage may fail, leading to persistent disease, repeat intervention, tonsillectomy, or early recurrence. This study aimed to identify factors associated with drainage failure. Methods: We conducted a retrospective single-centre study of patients admitted for PTA between 2019 and 2024. All patients underwent antibiotic therapy and surgical drainage by needle aspiration or incision and drainage. Drainage failure was defined as absence of pus evacuation, lack of clinical improvement within 72 h, need for quinsy tonsillectomy (QT), or recurrence within 30 days. Clinical and radiological variables and drainage techniques were analysed using univariate and multivariable analyses. Results: Eighty-four patients were included; drainage was successful in 68 (81%) and failed in 16 (19%). Previous ipsilateral PTA, smaller abscess diameter, multiloculation, and peritonsillar abscess with a concurrent intratonsillar abscess were significantly associated with failure. Needle aspiration showed a higher failure rate than incision and drainage (33.3% vs. 12.3%; OR 3.57; 95% CI 1.16–11.00; p = 0.035), but was not significant after adjustment (OR 2.87; 95% CI 0.63–14.04; p = 0.170). Peritonsillar abscess with a concurrent intratonsillar abscess (OR 57.30; 95% CI 2.37–9371.97; p = 0.011) and previous ipsilateral PTA (OR 20.68; 95% CI 4.77–108.22; p < 0.001) were independent predictors of failure. Conclusions: Peritonsillar abscess with a concurrent intratonsillar abscess and previous ipsilateral PTA were independently associated with drainage failure. These findings may help identify patients at increased risk of unsuccessful drainage and support individualized management.