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Deep neck infections: peritonsillar, retropharyngeal and Ludwig angina
A deep neck infection threatens the airway first; it is diagnosed by contrast CT, treated with IV antibiotics, and a defined abscess is drained — with securing the airway (sometimes by awake fibreoptic intubation or tracheostomy) coming before any surgery.
Why it matters in the exam
Peritonsillar abscess (quinsy) is the commonest deep infection in adolescents and young adults: severe one-sided sore throat, difficulty opening the mouth (trismus), a "hot potato" voice, drooling and deviation of the uvula to the healthy side. Treatment: needle aspiration or incision and drainage, antibiotics and pain control; tonsillectomy is reserved for recurrent episodes. Retropharyngeal abscess is common in children under age 5 (because of lymph nodes that later regress): fever, a stiff neck or head tilt, difficulty swallowing and sometimes stridor.
The key spaces: parapharyngeal (prestyloid and poststyloid, with the carotid artery and jugular vein), retropharyngeal, the "danger space" — between the alar and prevertebral fascia, reaching down to the diaphragm and allowing spread to the mediastinum — and prevertebral. Descending necrotising mediastinitis is a lethal complication. Lemierre syndrome: pharyngeal infection from Fusobacterium necrophorum with septic thrombosis of the internal jugular vein and septic emboli to the lungs.
Ludwig angina is bilateral cellulitis of the submandibular, sublingual and submental spaces, usually of dental origin (roots of the lower 2nd and 3rd molars, which lie below the mylohyoid muscle): a hard floor of mouth, a raised tongue and immediate danger to the airway. The airway is secured by awake fibreoptic intubation or tracheostomy under local anaesthesia. Usual antibiotics: ampicillin-sulbactam or clindamycin, with vancomycin when MRSA is suspected. A small abscess in a stable child can be treated with antibiotics for 24 to 48 hours before deciding on drainage.
Key points
- The airway comes first.
- Contrast CT for diagnosis.
- Peritonsillar: trismus and uvular deviation; aspiration or drainage.
- Ludwig: dental source, awake airway.
- Lemierre: Fusobacterium and jugular vein thrombosis.
Summary table
| Infection | Clue | Treatment |
|---|---|---|
| Peritonsillar abscess | Trismus, muffled voice, uvular deviation | Aspiration or drainage, antibiotics |
| Retropharyngeal abscess | Child under age 5, stiff neck, difficulty swallowing | CT; antibiotics, drainage for a large abscess |
| Parapharyngeal abscess | Neck swelling, trismus | CT; external or transoral drainage |
| Ludwig angina | Hard floor of mouth, raised tongue, dental source | Awake airway or tracheostomy, antibiotics, treat the tooth |
| Lemierre | Pharyngeal infection, venous thrombosis, lung emboli | Prolonged anti-anaerobic antibiotics |
| Descending mediastinitis | Chest pain, worsening after a neck infection | Chest CT and surgical drainage |
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Sources
- Cummings Otolaryngology: Head and Neck Surgery, 7th edition (2021) — Deep neck space infections
- Scott-Brown's Otorhinolaryngology Head and Neck Surgery, 8th edition (2018) — Peritonsillar abscess and deep neck infection
- Difficult Airway Society guidelines for awake tracheal intubation in adults, 2020 — Awake fibreoptic intubation
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.