Deep neck infection
Synonyms and keywords: cervical fascial space infection; DNI; perimandibular space infection

# Overview
Deep neck infection is a potentially life-threatening condition which arises from a septic nidus affecting one or more of the deep neck spaces.  Fever, neck pain, and neck swelling are the most prevalent symptoms in adults.  Pediatric patients commonly present with fever, neck mass, neck stiffness, sore throat, drooling, or poor oral intake.  Contrast-enhanced CT scan of the neck is recommended to scrutinize the extent of involvement and differentiate the nature of lesion.  Securing the airway is the key initial management for known or suspected deep neck infection.  In view of the rapidly progressive course of deep neck infection, patients should receive timely empiric treatment with broad-spectrum intravenous antibiotics covering Gram-positive cocci, Gram-negative bacilli, and/or anaerobes, tailored on the basis of clinical scenario, host immune status, and local antibiogram data.  Surgical interventions may be required for complicated cases.

# Pathophysiology

## Anatomic Considerations of Deep Neck Spaces
Based on their spatial relation to the hyoid, deep neck spaces may be divided into three anatomic groups:
- Spaces above the level of the hyoid
- Peritonsillar space
- Submandibular space
- Parapharyngeal space (lateral pharyngeal space or pharyngomaxillary space)
- Masticator space (temporal space)
- Buccal space
- Parotid space
- Spaces that involve the entire length of the neck
- Retropharyngeal space (retrovisceral space or retroesophageal space)
- Danger space
- Prevertebral space
- Carotid space (visceral vascular space)
- Spaces below the level of the hyoid
- Anterior visceral space (pretracheal space)

# Causes

## Aerobes

### Frequently Isolated Aerobes
- Viridans streptococci
- Klebsiella pneumoniae
- Staphylococcus aureus

### Less Frequently Isolated Aerobes
- Streptococcus pneumoniae
- Streptococcus pyogenes
- Neisseria species
- Haemophilus influenzae

## Anaerobes

### Frequently Isolated Anaerobes
- Peptostreptococcus species
- Prevotella species

### Less Frequently Isolated Anaerobes
- Bacteroides fragilis
- Porphyromonas species
- Fusobacterium species
- Eikenella corrodens

## Atypical Pathogens
- Actinomyces israelii
- Bartonella henselae

# Natural History, Complications, and Prognosis

## Complications
- Infection of the submandibular space may be complicated by Ludwig's angina, mediastinitis, osteomyelitis of the mandible, pleural effusion, empyema, or infection of carotid sheath structures.
- Infection of the carotid space may be complicated by Lemierre's syndrome leading to thrombosis of the internal jugular vein, aneurysm or rupture of the carotid artery, ipsilateral Horner's syndrome, or cranial nerve palsies of the CN IX through CN XII.
- Infection of the parapharyngeal space may be complicated by septicemia and complications related to carotid sheath involvement.
- Infection of the retropharyngeal space may be complicated by aspiration of pus from ruptured abscess, airway obstruction requiring intubation or tracheotomy, or cavernous sinus thrombosis.
- Infection of the danger space may be complicated by disseminated infection leading to mediastinitis, empyema, pneumonia, or septicemia.
- Necrotizing fasciitis may occur as a late sequela of deep neck infection in elderly patients, immunocompromised hosts, or poorly controlled diabetics.

# Diagnosis

## History
In the absence of acute respiratory distress, history taking should attempt to identify potential sources of the deep neck infection, such as any recent illness affecting oropharyngeal structures, dental caries or procedures, upper airway surgeries, penetrating injuries in the head and neck, or intravenous drug use.  Other pertinent history includes host immune status (e.g., human immunodeficiency virus infection, recent use of chemotherapeutic agent or corticosteroids) and past medical history of chronic hepatitis, diabetes mellitus, rheumatic disorders, or hematologic malignancy.  In these settings, patients are at an increased risk of rapidly progressive diseases or atypical clinical presentations not featured by marked inflammatory responses.

## Signs and Symptoms
Symptoms may reflect generalized or local inflammatory processes in response to the infection. Fever, neck pain, and neck swelling are the most prevalent symptoms in adults.  Dysphagia, odynophagia, drooling, hoarseness ("hot potato" voice), shortness of breath, trismus, or otalgia may also occur.  Pediatric patients commonly present with fever, neck mass, neck stiffness, sore throat, drooling, or poor oral intake.

## Physical Examination

### Head and Neck
- Palpation of the neck disclose localizing tenderness, swelling, or crepitus due to gas-producing organisms or trauma to the airway.

### Eyes
- Extraocular movement abnormalities or absent papillary light reflex may be indicative of orbital inflammation or abscess.

### Ear
- Examination of the ear canal may reveal erythema, tenderness, purulent discharge, or abnormalities of the eardrum.

### Mouth
- Pain or difficulty with mouth opening suggests dissenminated infection involving the parapharyngeal or masticator space.
- Decayed teeth with swollen dental alveoli may indicate odontogenic infection.
- Tenderness, edema, or purulent discharge at the floor of the mouth may be noted.

### Throat
- Examination of the throat may reveal inflammation and swelling of the epiglottis and other upper airway structures.

## Laboratory Findings
- Complete blood count with differential
- Basic metabolic panel
- Coagulation panel
- Culture of the blood and aspirates (aerobic and anaerobic bacteria, mycobacteria, fungi, or atypical pathogens)
- Erythrocyte sedimentation rate
- C-reactive protein

## Imaging Studies
- Lateral neck radiograph may demonstrate retropharyngeal or parapharyngeal abscesses.
- Chest radiograph may be useful when screening for intrathoracic processes such as mediastinitis or empyema.
- Dental radiograph may be useful in identifying odontogenic infections.
- Ultrasound may aid in distinguishing a drainable abscess from cellulitis.
- Contrast-enhanced CT scan of the neck is the standard of care and should be used to characterize the extent of involvement and differentiate the nature of lesion.
- Magnetic resonance imaging may be considered if high resolution of soft tissues is required.
- Magnetic resonance angiography may be used to evaluate vascular complications such as thrombosis, aneurysm, or rupture of the internal jugular vein and carotid artery.

# Treatment

## Airway Management
Securing the airway is the key initial management of any patient with suspected deep neck infection.  Airway patency should be confirmed before transporting the patient for radiographic evaluation.  A tracheotomy set should be made available and tracheotomy may be considered in cases where minimal airway lumen can be visualized.  Other options of airway interventions include endotracheal intubation, nasal fiberoptic intubation, and cricothyrotomy.

## Fluid Resuscitation
Intravenous access should be established for rapid administration of medications and fluids.  Timely infusion of 1 to 2 liters of isotonic fluids is necessary for treating dehydration as a result of poor intake associated with dysphagia, odynophagia, or trismus in patients with deep neck infections affecting peritonsillar or retropharyngeal space.

## Antibiotic Therapy
- Deep neck infection
- 1. Empiric antimicrobial therapy
- 1.1 Community-acquired deep neck infection
- Preferred regimen: Ampicillin-Sulbactam 1.53.0 g IV q6h OR Clindamycin 600900 mg IV q8h OR Moxifloxacin 400 mg IV q24h (if Eikenella is suspected)
- 1.2 Nosocomial deep neck infection or immunocompromised host
- Preferred regimen: Ticarcillin-Clavulanate 3 g IV q6h OR Piperacillin-Tazobactam 3 g IV q6h OR Imipenem-Cilastatin 500 mg IV q6h OR Ciprofloxacin 400 mg IV q12h OR Levofloxacin 750 mg IV q24h
- 1.3 Deep neck infection with high-risk of MRSA
- Preferred regimen: (Clindamycin 600900 mg IV q8h OR Trimethoprim-Sulfamethoxazole 10 mg/kg/day IV q8h AND Vancomycin 1 g IV q12h
- 1.4 Necrotizing fasciitis
- Preferred regimen: Ceftriaxone 2 g IV q8h AND Clindamycin 600900 mg IV q8h AND Metronidazole 500 mg IV q6h
- 2. Specific anatomic considerations
- 2.1 Submandibular space infections including Ludwig angina
- Causative pathogens
- Viridans and other streptococci
- Peptostreptococcus
- Bacteroides
- Other oral anaerobes
- Preferred regimen (immunocompetent host): (Penicillin G 24 MU IV q46h AND Tobramycin 2 mg/kg IV q8h) OR Ampicillin-Sulbactam 2 g IV q4h OR Clindamycin 600 mg IV q6h OR Doxycycline 200 mg IV q12h OR Cefoxitin 2 g IV q6h OR Cefotetan 2 g IV q12h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Meropenem 1 g IV q8h OR Gatifloxacin 200 mg IV q24h
- 2.2 Lateral pharyngeal or retropharyngeal space infections (odontogenic)
- Causative pathogens
- Viridans and other streptococci
- Staphylococcus
- Peptostreptococcus
- Bacteroides
- Other oral anaerobes
- Preferred regimen (immunocompetent host): (Penicillin G 24 MU IV q46h AND Metronidazole 0.5 g IV q6h) OR Ampicillin-Sulbactam 2 g IV q4h OR Clindamycin 600 mg IV q6h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h OR Gatifloxacin 400 mg IV q24h
- 2.3 Lateral pharyngeal or retropharyngeal space infections (rhinogenic)
- Causative pathogens
- Streptococcus pyogenes
- Fusobacterium
- Peptostreptococcus
- Other oral anaerobes
- Preferred regimen (immunocompetent host): Penicillin G 24 MU IV q46h OR (Ciprofloxacin 200 mg q12h AND Metronidazole 0.5 g IV q6h) OR Gatifloxacin 400 mg IV q24h OR Clindamycin 600 mg IV q6h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h OR Gatifloxacin 400 mg IV q24h
- 2.4 Lateral pharyngeal or retropharyngeal space infections (otogenic)
- Causative pathogens
- Streptococcus pneumoniae
- Haemophilus influenzae
- Viridans and other streptococci
- Peptostreptococcus
- Bacteroides
- Other oral anaerobes
- Preferred regimen (immunocompetent host): Penicillin G 24 MU IV q46h OR (Ciprofloxacin 200 mg q12h AND Metronidazole 0.5 g IV q6h) OR Gatifloxacin 400 mg IV q24h OR Clindamycin 600 mg IV q6h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h OR Gatifloxacin 400 mg IV q24h
- 2.5 Peritonsillar abscess (quinsy)
- Causative pathogens
- Viridans and other streptococci
- Peptostreptococcus
- Bacteroides
- Other oral anaerobes
- Preferred regimen (immunocompetent host): (Penicillin G 24 MU IV q46h AND Metronidazole 0.5 g IV q6h) OR Ampicillin-Sulbactam 2 g IV q4h OR Clindamycin 600 mg IV q6h OR Cefoxitin 2 g IV q6h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h
- 2.6 Suppurative parotitis
- Causative pathogens
- Staphylococcus
- Viridans and other streptococci
- Bacteroides
- Peptostreptococcus
- Other oral anaerobes
- Preferred regimen (immunocompetent host): (Nafcillin 1.5 g IV q46h AND Metronidazole 0.5 g IV q6h) OR Clindamycin 600 mg IV q6h
- Preferred regimen (immunocomppromised host): (Vancomycin 0.5 g IV q6h AND Cefotaxime 2 g IV q6h) OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h
- 2.7 Extension of osteomyelitis from prevertebral space infection
- Causative pathogens
- Staphylococcus
- Facultative gram-negative bacilli
- Preferred regimen (immunocompetent host): (Nafcillin 1.5 g IV q46h AND Metronidazole 0.5 g IV q6h) OR Ciprofloxacin 200 mg q12h
- Preferred regimen (immunocomppromised host): (Vancomycin 0.5 g IV q6h AND Cefotaxime 2 g IV q6h) OR Ceftizoxime 4 g IV q8h OR Imipenem 500 mg IV q6h
- 2.8 Pott's puffy tumor (frontal osteitis)
- Causative pathogens
- Streptococcus pyogenes
- Fusobacterium
- Peptostreptococcus
- Other oral anaerobes
- Preferred regimen (immunocompetent host): Penicillin G 24 MU IV q46h OR (Ciprofloxacin 200 mg q12h AND Metronidazole 0.5 g IV q6h) OR Gatifloxacin 400 mg IV q24h OR Clindamycin 600 mg IV q6h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h OR Gatifloxacin 400 mg IV q24h
- 2.9 Malignant otitis media
- Causative pathogens
- Pseudomonas aeruginosa
- Preferred regimen (immunocompetent host): Ciprofloxacin 200 mg q12h OR (Tobramycin 2 mg/kg IV q8h AND Ceftazidime 2 g IV q6h) OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h
- Preferred regimen (immunocomppromised host): (Tobramycin 2 mg/kg IV q8h AND Ceftazidime 2 g IV q6h) OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h
- 2.10 Petrous osteitis
- Causative pathogens
- Pseudomonas aeruginosa
- Preferred regimen (immunocompetent host): Ciprofloxacin 200 mg q12h OR (Tobramycin 2 mg/kg IV q8h AND Ceftazidime 2 g IV q6h) OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h
- Preferred regimen (immunocomppromised host): (Tobramycin 2 mg/kg IV q8h AND Ceftazidime 2 g IV q6h) OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h
- 2.11 Septic jugular thrombophlebitis (Lemierre syndrome)
- Causative pathogens
- Fusobacterium
- Viridans and other streptococci
- Staphylococcus
- Peptostreptococcus
- Bacteroides
- Other oral anaerobes
- Preferred regimen (immunocompetent host): (Penicillin G 24 MU IV q46h AND Metronidazole 0.5 g IV q6h) OR Ampicillin-Sulbactam 2 g IV q4h OR Clindamycin 600 mg IV q6h
- Preferred regimen (immunocomppromised host): Cefotaxime 2 g IV q6h OR Ceftizoxime 4 g IV q8h OR Piperacillin 3 g IV q4h OR Imipenem 500 mg IV q6h OR Imipenem 500 mg IV q6h OR Gatifloxacin 400 mg IV q24h

## Surgical Management
- Surgical drainage may be indicated in the following circumstances:

# Related Chapters
- Cavernous sinus thrombosis
- Horner's syndrome
- Lemierre's syndrome
- Ludwig's angina