Which anatomical space is involved in a peritonsillar abscess?

Explanation

## Anatomy of Peritonsillar Abscess **Key Point:** A peritonsillar abscess (quinsy) develops in the potential space between the **tonsillar capsule (tonsil)** and the **superior pharyngeal constrictor muscle**, which is the classic anatomical definition of the peritonsillar space as described in standard ENT and anatomy textbooks (Scott-Brown's Otorhinolaryngology, Dhingra's ENT). ### Anatomical Spaces of the Oropharynx | Space | Boundaries | Contents | Abscess Risk | |-------|-----------|----------|---------------| | **Peritonsillar** | Tonsillar capsule medially; superior pharyngeal constrictor laterally | Loose areolar tissue | **HIGH** — most common deep neck space infection | | Intratonsillar | Within tonsillar crypts | Tonsillar tissue | Moderate — suppuration within gland | | Retropharyngeal | Posterior to pharyngeal constrictors | Loose areolar tissue, lymph nodes | Moderate — more common in children | | Parapharyngeal | Lateral to superior pharyngeal constrictor | Neurovascular structures | High — can be life-threatening | **High-Yield:** The peritonsillar space is bounded **medially by the fibrous capsule of the tonsil** and **laterally by the superior pharyngeal constrictor muscle**. The loose areolar tissue within this space has poor lymphatic drainage, making it the ideal site for abscess formation following acute tonsillitis. ### Clinical Anatomy **Clinical Pearl:** Pus accumulation in the space between the tonsil and the superior pharyngeal constrictor causes: - Bulging of the soft palate and anterior pillar medially - Displacement of the tonsil medially and inferiorly - Trismus (due to irritation of the medial pterygoid muscle) - Dysphagia and "hot potato" (muffled) voice - Uvular deviation to the contralateral side **Why Option A is incorrect:** The posterior tonsillar pillar (palatopharyngeus muscle) is NOT the lateral boundary of the peritonsillar space. The superior pharyngeal constrictor muscle forms the true lateral wall. The anterior and posterior tonsillar pillars (palatoglossus and palatopharyngeus) form the tonsillar fossa but are not the defining boundaries of the peritonsillar abscess space. **Reference:** Dhingra PL, *Diseases of Ear, Nose and Throat*, 7th ed.; Scott-Brown's Otorhinolaryngology, Head and Neck Surgery, 8th ed. — both define the peritonsillar space as lying between the tonsillar capsule and the superior pharyngeal constrictor. **Warning:** Do not confuse peritonsillar abscess with retropharyngeal abscess (posterior to the pharyngeal constrictor) or parapharyngeal abscess (lateral to the superior pharyngeal constrictor). These are different deep neck spaces with different drainage patterns and complications.