PANCE Blueprint EENT (7%)

Deep neck infection

Patient will present as → a 33-year-old male presents to the emergency department with a 3-day history of severe throat pain, fever, and difficulty swallowing. He mentions that the pain has progressively worsened, now radiating to his ear, and describes a feeling of tightness and swelling in his neck. He also reports a muffled voice and difficulty breathing, particularly when lying down. His medical history is notable for untreated dental caries and a recent upper respiratory tract infection. On examination, he is febrile with a temperature of 39.2°C (102.6°F). Inspection of the oropharynx is limited due to trismus. There is noticeable swelling and tenderness to palpation on the left side of his neck, with overlying erythema and warmth. His voice is hoarse, and he appears to be in respiratory distress with stridor noted on auscultation. Laboratory tests reveal leukocytosis. A CT scan of the neck with contrast shows a large abscess in the left parapharyngeal space with surrounding cellulitis, consistent with a deep neck infection. The patient is admitted to the intensive care unit for airway monitoring given his respiratory distress. Immediate intravenous broad-spectrum antibiotics are initiated, and an urgent otolaryngology consultation is obtained for possible surgical drainage. He is also evaluated by a dentist for management of his dental caries, which is suspected to be the source of the infection.

Deep neck space infections most commonly arise from a septic focus of the mandibular teeth, tonsils, parotid gland, deep cervical lymph nodes, middle ear, or sinuses

  • Deep neck space infections often have a rapid onset and can progress to life-threatening complications
  • Staphylococcus aureus is the most common cause of deep neck infections in immunocompetent individuals
  • Classic manifestations of these infections include high fever, systemic toxicity, and local signs of erythema, edema, and fluctuance

Minor trauma triggering cervicofacial necrotizing fasciitis from an odontogenic abscess. Image by Jain S, Nagpure PS, Singh R, Garg D - CC 2.0

Here is a table summarizing the most common deep neck infections, including their locations, common causes, and symptoms:

Infection Location Common Causes Symptoms/Signs
Peritonsillar Abscess Around the tonsils Streptococcus pyogenes, Staphylococcus aureus, anaerobes Severe sore throat, difficulty swallowing, fever, "hot potato" voice

Uvular deviation to the contralateral tonsillar pillar

Retropharyngeal Abscess Retropharyngeal space, behind the pharynx Streptococcus pyogenes, Staphylococcus aureus, anaerobes Fever, neck stiffness, sore throat, difficulty swallowing, respiratory distress

Midline uvula

Widening of prevertebral space on lateral neck radiograph

Parapharyngeal Abscess Parapharyngeal space, lateral to the pharynx Streptococcus species, Staphylococcus aureus, anaerobes Fever, trismus (lockjaw), neck pain, swelling
Ludwig's Angina Submandibular space, beneath the floor of the mouth Streptococcus species, Staphylococcus aureus, anaerobes Rapidly progressing cellulitis, swelling, pain in the floor of the mouth, difficulty swallowing, potentially compromised airway
Suppurative Lymphadenitis Lymph nodes in the neck Streptococcus pyogenes, Staphylococcus aureus Swollen, tender lymph nodes, fever, sometimes drainage of pus
Necrotizing Fasciitis Fascia and subcutaneous tissues in the neck Polymicrobial, including Group A Streptococcus, anaerobes Severe pain, rapid progression, fever, signs of systemic toxicity
Lemierre's Syndrome Jugular vein thrombophlebitis, often secondary to oropharyngeal infection Fusobacterium necrophorum Sore throat, fever, neck swelling, septic emboli leading to potential systemic complications like lung abscesses

Computed tomography (CT) with contrast is the imaging modality of choice for the diagnosis of deep neck space infection

  • MRI is useful for assessing the extent of soft tissue involvement and for delineating vascular complications
  • Plain radiography is of limited utility for the evaluation of deep neck space infection

The most common organisms isolated from deep neck space infections are staphylococcus aureus, including MRSA (22.5%) followed by streptococcus species (20%)

  • For deep neck space infections that involve a drainable collection, aspiration or surgical drainage should be performed
  • Antibiotic treatment depends on the location of infection - options include nafcillin, vancomycin, ciprofloxacin, etc.
  • For parapharyngeal, retropharyngeal, or prevertebral space infections, therapy should generally be continued for two to three weeks
Question 1

A 35-year-old man presents to the emergency department with swelling on the right side of his neck and difficulty swallowing that has worsened over the last two days. He recently had a toothache in the lower right jaw but didn't go to the dentist. He is febrile with a temperature of 102.3°F. Which of the following is the most likely predisposing factor for this patient's condition?

Recent strep throat
While strep throat can occasionally lead to complications such as peritonsillar abscess, it is less likely to be directly involved in the development of deep neck space infections.
History of head and neck cancer
Head and neck cancer, and its treatments (radiation), can make individuals more susceptible to infections, but are not the primary driver for an otherwise healthy individual to develop a deep neck infection.
Recent upper respiratory infection
Recent upper respiratory infection: Upper respiratory infections are common but they typically don't lead to complications involving deep neck spaces.
Dental caries
Chronic sinusitis
Chronic sinusitis can involve adjacent structures, but deep neck infections usually stem from oral or pharyngeal sources.
Question 1 Explanation: 
Dental infections are a recognized risk factor for the development of deep neck infections. Poor dental hygiene and periodontal disease can lead to infections that spread to the deep neck spaces, potentially causing life-threatening complications due to the proximity to vital structures.
Question 2
Which of the following is the most common cause of a deep neck space infection in an otherwise healthy individual?
Group A streptococcus
Less common cause than S. aureus in deep neck infections.
Staphylococcus aureus
Haemophilus influenzae
Uncommon cause in adults without risk factors.
Mycobacterium tuberculosis
Atypical cause in immunocompetent patients.
Actinomyces species
Unusual cause of deep neck infections.
Question 2 Explanation: 
Staphylococcus aureus is the most common cause of deep neck infections in immunocompetent individuals. Group A streptococcus is less common. Haemophilus influenzae, Mycobacterium tuberculosis, and Actinomyces are less likely pathogens in an otherwise healthy person. Appropriate antibiotic coverage for S. aureus is important in treatment.
Question 3
A 65-year-old woman has a 3-day history of throat pain, neck swelling, and fevers. Physical exam shows fullness along the left side of her neck and deviation of the trachea to the right. Which of the following is the most appropriate next step in diagnosis?
Lateral neck X-ray
May show some abnormalities but lacks the detail of CT scans for diagnosing deep neck infections.
Contrast-enhanced CT scan of the neck
MRI of the neck
Provides excellent soft tissue contrast but is less accessible and more time-consuming than CT, making it less ideal for initial assessment.
Ultrasound of the neck
Useful for evaluating superficial structures but may not adequately visualize deep neck spaces.
Direct laryngoscopy
Invasive and not the first-line diagnostic tool for deep neck infections; more useful for assessing airway patency and involvement.
Question 3 Explanation: 
A contrast-enhanced CT scan of the neck is the most appropriate initial diagnostic test for a patient presenting with symptoms suggestive of a deep neck infection. CT scans can provide detailed images of the neck's soft tissues, including any abscess formation, and help delineate the extent of the infection.
Question 4
A 38-year-old man is diagnosed with a submandibular space abscess. He undergoes CT-guided drainage and cultures grow methicillin-resistant S. aureus. Which of the following is the most appropriate targeted antibiotic therapy?
A first generation cephalosporin that does not cover MRSA.
Active against MRSA but resistance is possible.
A penicillin without MRSA coverage.
A macrolide antibiotic that does not treat MRSA.
Question 4 Explanation: 
For a deep neck infection caused by methicillin-resistant S. aureus, vancomycin is the most appropriate antibiotic choice to cover this organism. Cephalexin, amoxicillin, and azithromycin would not treat MRSA. Clindamycin has activity against MRSA but resistance can emerge, making vancomycin a safer choice.
There are 4 questions to complete.
Shaded items are complete.

References: Merck Manual · UpToDate

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