A hidden diagnosis in the tonsil: recognising and differentiating intratonsillar abscess

Peritonsillar abscess (PTA) and intratonsillar abscess (ITA) are distinct entities, but the latter is often overlooked due to its rarity and diagnostic difficulty. This study compares their clinical, laboratory, and microbiological profiles to identify distinguishing features.

This single-centre retrospective study included 367 patients diagnosed with PTA (n = 311) or ITA (n = 56) between 2019 and 2025. Demographics, symptoms, laboratory markers (e.g., white blood cells [WBC], neutrophils, lymphocytes, large unstained cells [LUC], C-reactive protein, sodium, neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, and platelet-to-WBC ratio [PWR]), culture results, imaging, drainage outcomes, and hospital stay were analysed comparatively.

PTA cases showed significantly higher WBC, neutrophil counts, and drainage volumes, with 80.8% drainage success versus 19.1% in ITA (p < 0.001). LUC and PWR were significantly elevated in ITA, suggesting a lymphocyte-dominant response. Fever was more frequent in ITA, while trismus and local spread were more characteristic of PTA.

ITA typically presents with smaller abscesses and limited systemic involvement, often responding to conservative treatment. Recognising ITA as a distinct clinical entity may improve diagnosis and management strategies.