Deep Neck Infection


  • History: in pre-antibiotic era, 70% of deep neck infections occurred due to spread from tonsillar or pharyngeal infections
  • Risk Factors for Deep Neck Infection

Etiologic Prevalence by Age Group

  • Childen: tonsillitis was the most common source of deep neck infection in a 1995 study of 117 cases occurring over 6-year period [MEDLINE]
    • Peritonsillar Infections (tonsillitis, etc): 49% of cases
    • Retropharyngeal Infections: 22% of cases
    • Submandibular Infections: 14% of cases
    • Buccal Infections: 11% of cases
    • Parapharyngeal Space Infections: 2% of cases
    • Canine Space Infections: 2% of cases
  • Adults: odontogenic infection is the most common source of deep neck infection


Contiguous Spread of Infection

  • Cervical Lymphadenitis (see Lymphadenopathy, [[Lymphadenopathy]]): inflammation/enlargement of cervical lymph nodes, leading to suppuration and/or abscess formation
  • Dental Infection/Abscess (see Dental Abscess, [[Dental Abscess]]): odontogenic infection is the most common etiology in adults
  • Infected Branchial Cleft Anomaly (branchial cleft cyst, etc)
  • Infected Thyroglossal Duct Cyst
  • Laryngopyocele
  • Mastoiditis/Petrous Apicitis
    • Bezold Abscess: abscess in sternocleidomastoid muscle (due to extension from mastoiditis)
  • Necrosis/Infection of Malignant Cervical Lymph Node or Mass
  • Pyogenic Thyroiditis (see Thyroiditis, [[Thyroiditis]])
  • Sialadenitis (see Sialadenitis, [[Sialadenitis]])
  • Tonsillitis/Pharyngitis (see Pharyngitis, [[Pharyngitis]])): tonsillitis is the most common etiology in children


Penetrating Trauma to Oral Cavity/Pharynx

  • Esophageal Laceration/Perforation (see Esophageal Perforation, [[Esophageal Perforation]]): ingestion of fish bones or sharp objects
  • Foreign Body Aspiration
  • Gun Shot Wounds
  • Knife/Penetrating Object Wounds


  • Idiopathic Deep Neck Infection: 20-50% of cases
  • Intravenous Drug Abuse (IVDA)


  • Typically Mixed Aerobic + Anerobic Infections: usually with predominance of oral flora organisms
    • Polymicrobial in approximately 90% of cases
  • Specific Organisms
    • Streptococcus pyogenes (group A beta-hemolytic Strep) (see Streptococcus Pyogenes, [[Streptococcus Pyogenes]]): commonly isolated
    • Streptococcus pneumoniae (see Streptococcus Pneumoniae, [[Streptococcus Pneumoniae]]): commonly isolated
    • Viridans Group Streptococci (see Viridans Group Streptococci, [[Viridans Group Streptococci]]): commonly isolated
    • Staphylococcus aureus (see Staphylococcus Aureus, [[Staphylococcus Aureus]]): commonly isolated
    • Fusobacterium nucleatum (see Fusobacterium, [[Fusobacterium]]): commonly isolated
    • Bacteroides melaninogenicus (see Bacteroides, [[Bacteroides]]): commonly isolated
    • Bacteroides oralis (see Bacteroides, [[Bacteroides]]): commonly isolated
    • Spirochaeta: commonly isolated
    • Peptostreptococcus (see Peptostreptococcus, [[Peptostreptococcus]]): commonly isolated
    • Neisseria Species (see Neisseria, [[Neisseria]]): commonly isolated
    • Pseudomonas Species (see Pseudomonas, [[Pseudomonas]]): occasionally isolated
    • Escherichia coli (see Escherichia Coli, [[Escherichia Coli]]): occasionally isolated
    • Haemophilus influenzae (see Haemophilus Influenzae, [[Haemophilus Influenzae]]): occasionally isolated


  • Neck CT with Intravenous Contrast: gold standard for imaging deep neck spaces
  • Neck MRI: may alternatively be used
  • Ultrasound: may help distinguish between phlegmon and abscess, give information about the condition of surrounding vessels, and guide fine needle aspiration
  • Carotid Angiogram/Venogram: may be helpful when carotid, jugular, or innominate vessels are involved

Clinical Features by Anatomic Space

Parapharyngeal Space

  • Anatomy: comprised of the lateral pharyngeal space, the pharyngomaxillary space, the pterygomaxillary space, and the pterygopharyngeal space
  • Contents
    • Anterior Compartment: internal maxillary artery, inferior alveolar nerve, lingual nerve, and auriculotemporal nerve
    • Posterior Compartment: carotid sheath (carotid artery, internal jugular vein, vagus nerve), glossopharyngeal and hypoglossal nerves, sympathetic chain, and lymphatics, accessory nerve (this nerve is relatively protected, as it is located behind the sternocleidomastoid muscle)
  • Anatomic Communication: parapharyngeal space is a centally located space, with connections to the other deep neck spaces
    • Infections that spread from the peritonsillar space (this was the most commonly affected space in the pre-antibiotic era): tonsillitis, pharyngitis, dental infection, sialadenitis, nasal infections, or mastoid/Bezold abscess
    • Posteromedially, parapharyngeal space communicates with the retropharyngeal space
    • Inferiorly, parapharyngeal space communicates with the submandibular space
    • Laterally, parapharyngeal space communicates with the masticator space
  • Clinical Features with Abscess in This Space
    • Trismus
    • Medial Displacement of the Lateral Pharyngeal Wall and Tonsil
    • Drooling
    • Dysphagia/Odynophagia (see Dysphagia, [[Dysphagia]] and Odynophagia, [[Odynophagia]])

Retropharyngeal Space

  • Anatomy
    • The retropharyngeal space is sometimes considered a third medial compartment within the parapharyngeal space because these two spaces communicate laterally
    • This space lies between the visceral division of the middle layer of the deep cervical fascia around the pharyngeal constrictors and the alar division of the deep layer of deep cervical fascia posteriorly
    • It extends from the skull base to the tracheal bifurcation around T2 where the visceral and alar divisions fuse
  • Contents: retropharyngeal lymphatics
  • Anatomic Communication
    • Entry
      • Traumatic/Foreign Body Perforation of Posterior Pharyngeal Wall: common in adult cases
      • Traumatic/Foreign Body Perforation of Esophagus: common in adult cases
      • Extension from Parapharyngeal Space Abscess (resulting from infections in nose, adenoids, nasopharynx, and sinuses): respiratory tract infections account for >60% of retropharyngeal abscesses in children
        • Retropharyngeal lymph nodes tend to regress by about age 5 years, making infection in this space much more common in children than adults
    • Exit
      • Extension into paravertebral space
  • Clinical Features with Abscess in This Space (see Retropharyngeal Abscess, [[Retropharyngeal Abscess]])
    • Anterior Displacement of One or Both Sides of Posterior Pharyngeal Wall: due to involvement of lymph nodes, which are distributed lateral to the midline fascial raphe
    • Upper Airway Obstruction (see Obstructive Lung Disease, [[Obstructive Lung Disease]]): at level of pharynx

Prevertebral Space

  • Anatomy
    • Located anterior to vertebral bodies and posterior to the prevertebral division of the deep layer of the deep cervical fascia
    • Located posterior to the danger space
    • Laterally, it is bounded by the fusion of the prevertebral fascia with the transverse processes of the vertebral bodies
    • It extends from the skull base to the coccyx
  • Anatomic Communication
    • Entry
      • Extension from other sites into prevertebral space (most common etiology)
      • Traumatic instrumentation of prevertebral space (second most common etiology)
    • Exit
      • Extension into danger space or mediastinum
  • Clinical Features with Abscess in This Space
    • Vertebral Involvement: osteomyelitis, spinal instability

Danger Space (Alar Space)

  • Anatomy: spread within the danger space tends to occur rapidly because of loose areolar tissue in this region
    • Located posterior to the retropharyngeal space and anterior to the prevertebral space
    • It is a midline space without a midline raphe, so infections can occur bilaterally
    • Located between the alar and prevertebral divisions of the deep layer of the deep cervical fascia
    • Extends from the skull base to the posterior mediastinum and diaphragm
    • Laterally, it is limited by the fusion of the alar and prevertebral division with the transverse processes of the vertebrae
    • Some authors consider the danger space a component of the prevertebral space
  • Anatomic Communication
    • Entry
      • Extension from retropharyngeal, parapharyngeal, or prevertebral space abscesses
    • Exit
      • Extension into mediastinum -> resulting in empyema/sepsis

Masticator Space

  • Anatomy
    • Located laterally to the medial pterygoid fascia and medially to the masseter muscle
    • Bounded by the sphenoid bone, the posterior aspect of the mandible, and the zygomatic arch
    • Inferior to the temporal space
    • Anterolateral to the parapharyngeal space
  • Anatomic Communication
    • Entry
      • Dental Infections (particularly of the third mandibular molars)
      • Removal of Suspension Wires following Reduction and Fixation of Facial Fractures
    • Exit
      • Extension to parapharyngeal, parotid, or temporal spaces
  • Contents: masseter, pterygoids, ramus and body of the mandible, temporalis tendon, and the inferior alveolar vessels and nerve
  • Clinical Features with Abscess in This Space
    • Trismus: commonly seen as part of the initial presentation, but may also persist chronically

Submandibular Space

  • Anatomy: bounded inferiorly by the superficial layer of the deep cervical fascia extending from the hyoid to the mandible, laterally by the body of the mandible, and superiorly by the mucosa of the floor of mouth
  • Anatomic Communication
    • Entry
      • Oral Trauma
      • Submaxillary or Sublingual Sialadenitis
      • Dental Abscess of Mandibular Teeth
    • Exit
      • Extension to parapharyngeal and retropharyngeal spaces
  • Physiology
    • Inflammation and cellulitis of the submandibular space, usually originating in the submaxillary space and spreading to the sublingual space via the fascial planes (not via the lymphatics)
    • Induration of floor of mouth (which does not necessarily require a focal abscess) -> tongue is forced upward and backward, resulting in airway obstruction
  • Clinical Features with Abscess in This Space: Ludwig’s Angina (see Ludwig’s Angina, [[Ludwigs Angina]])
    • Drooling
    • Trismus
    • Pain
    • Dysphagia
    • Submandibular Mass
    • Upper Airway Obstruction (see Obstructive Lung Disease, [[Obstructive Lung Disease]])
  • Treatment
    • Tracheostomy: required for airway management
    • Antibiotics
  • Prognosis: in pre-aintibiotic era, mortality was 50% -> current mortality rate is <5%

Carotid (Visceral Vascular) Space

  • Anatomy: potential space within the carotid sheath
  • Anatomic Communication
    • Entry
      • Intravenous Drug Abuse: when attmepting to access the internal jugular vein
      • Extension from parapharyngeal space
  • Contents: carotid artery, internal jugular vein, vagus nerve, and sympathetic postganglionic fibers
  • Clinical Features with Abscess in This Space
    • Carotid Artery Thrombosis/Aneurysm/Rupture
    • Horner Syndrome (see Horner Syndrome, [[Horner Syndrome]]): due to involvement of cervical sympathetics
    • Internal Jugular Vein Thrombosis (see Internal Jugular Vein Thrombosis, [[Internal Jugular Vein Thrombosis]])
    • Lemierre’s Syndrome (see Lemierres Syndrome, [[Lemierres Syndrome]])
    • Septic Pulmonary Embolism (see Septic Embolism, [[Septic Embolism]]): due to internal jugular vein thrombophlebitis

Pretracheal (Anterior Visceral) Space

  • Anatomy
    • Enclosed by the visceral division of the middle layer of the deep cervical fascia and lies immediately anterior to the trachea
    • Extends from the thyroid cartilage to the superior mediastinum
  • Anatomic Communication
    • Entry
      • Perforation of the anterior esophageal wall by endoscopic instrumentation/foreign bodies/trauma
  • Clinical Features with Abscess in This Space (see Pretracheal Abscess, [[Pretracheal Abscess]])

Peritonsillar Space

  • Epidemiology: peritonsillar abscesses (due to tonsillar infections) represent the most common type of deep neck space abscess
  • Anatomy: located lateral to tonsils
    • Patients who have had their tonsils removed effectvely lose this space, but they can still develop a peritonsillar abscess
  • Anatomic Commnuication
    • Exit
      • Extension to the parapharyngeal space
  • Clinical Features with Abscess in This Space (see Peritonsillar Abscess, [[Peritonsillar Abscess]])
    • Upper Airway Obstruction (see Obstructive Lung Disease, [[Obstructive Lung Disease]])
    • Trismus
    • Odynophagia (see Odynophagia, [[Odynophagia]])
    • Drooling
    • “Hot Potato” Voice
    • Fever (see Fever, [[Fever]])
    • Uvular Deviation
    • Palatal Asymmetry
    • Medial Displacement of Tonsil
    • Throat Pain
    • Tonsillar Erythema/Exudates: however, these may be mild, even in the presence of a peritonsillar abscess

Parotid Space

  • Epidemiology: abscesses in this space usually occur in dehydrated, debilitated patients with poor oral hygiene who develop salivary duct obstruction
  • Anatomic Commnuication
    • Exit
      • Superomedially, extension into the parapharyngeal space
  • Contents: external carotid artery, posterior facial vein, and facial nerve
  • Clinical Features with Abscess in This Space
    • Parotid Region Edema/Erythema/Pain
    • Fever (see Fever, [[Fever]])
    • Trismus: occurs late

Temporal Space

  • Anatomy: located between the temporalis fascia and the periosteum of the temporal bone
  • Contents: internal maxillary artery, inferior alveolar artery and nerve
  • Clinical Features with Abscess in This Space
    • Temporal Region Pain
    • Trismus
    • Deviation of Mandible

Path of Contiguous Spread of Infection



  • Airway Management: first priority
  • Surgical Drainage
  • Antibiotics/Treatment of Sepsis


  • Head and neck space infections in infants and children. Otolaryngol Head Neck Surg. Mar 1995;112(3):375-82 [MEDLINE]
  • Bacteriology of retropharyngeal abscess in children. Pediatr Infect Dis J. Aug 1990;9(8):595-7 [MEDLINE]
  • Laryngopyocele. JBR-BTR. 2012 Mar-Apr;95(2):74-6 [MEDLINE]
  • Retropharyngeal abscess in children: the rising incidence of methicillin-resistant Staphylococcus aureus. Pediatr Infect Dis J. 2012 Jul;31(7):696-9 [MEDLINE]