In peritonsillar abscess, which anatomical space is primarily involved?

Explanation

## Anatomy of Peritonsillar Abscess **Key Point:** A peritonsillar abscess (PTA) is a localized collection of pus in the space between the tonsillar capsule and the superior pharyngeal constrictor muscle — the **supratonsillar space**. ### Anatomical Spaces of the Pharynx | Space | Boundaries | Clinical Significance | |---|---|---| | **Supratonsillar space (lateral pharyngeal space)** | **Between tonsillar capsule and superior pharyngeal constrictor** | **Primary site of peritonsillar abscess** | | Retropharyngeal space | Between pharyngeal wall and prevertebral fascia | Retropharyngeal abscess (different entity) | | Parapharyngeal (lateral pharyngeal) space | Lateral to pharyngeal wall | Risk of airway compromise if infected | | Submandibular space | Below mandible | Involvement in Ludwig's angina | **High-Yield:** The supratonsillar space is bounded medially by the tonsillar capsule and laterally by the superior pharyngeal constrictor muscle. This is the anatomical plane where pus accumulates in peritonsillar abscess. ### Clinical Anatomy **Clinical Pearl:** The peritonsillar abscess typically develops at the **superior pole** of the tonsil (supratonsillar location) and can spread to the parapharyngeal space if untreated, risking airway obstruction and mediastinitis. **Mnemonic:** **SPC** = Superior Pharyngeal Constrictor — the muscle that forms the lateral boundary of the supratonsillar space where PTA forms. ### Clinical Implications Understanding this anatomy is crucial for: - Recognizing the classic intraoral bulge at the superior pole of the soft palate - Performing safe needle aspiration or incision and drainage - Predicting potential spread to deeper neck spaces - Managing airway compromise risk