What are some deep tissue infections of the neck?

Deep Tissue Infections of the Neck

Deep tissue infections of the neck include peritonsillar and pharyngeal abscesses, retropharyngeal abscess, parapharyngeal abscess, submandibular abscess, sublingual abscess, Ludwig's angina, and cervical lymphadenitis, which can arise from odontogenic, oropharyngeal, or exogenous sources. 1

Classification by Anatomical Location

Odontogenic Origin Infections

These infections arise from endogenous periodontal or gingival flora and include: 1

• Deep space abscesses involving:

  • Retropharyngeal space 1
  • Parapharyngeal space 1
  • Submandibular space 1, 2
  • Sublingual space 1

• Ludwig's angina - a particularly severe bilateral submandibular infection that represents 28.94% of deep neck space infections 2

• Cervical lymphadenitis 1

• Peritonsillar and pharyngeal abscesses 1

Odontogenic infections are the most common cause of deep neck space infections, accounting for 34-42% of cases, followed by tonsillar and pharyngeal infections at 27-28%. 2, 3

Oropharyngeal Origin Infections

These infections involve oropharyngeal flora and include: 1

• Epiglottitis - requires extreme caution as the epiglottis may swell dramatically and cause sudden tracheal occlusion 1

• Mastoiditis 1

• Suppurative parotitis and salivary tissue inflammation 1

Exogenous Origin Infections

These are caused by pathogens not part of the oral flora: 1

• Malignant otitis externa 1
• Animal bites and trauma 1
• Irradiation burns 1
• Complications of surgical procedures 1

Life-Threatening Complications

Deep neck infections can progress to potentially fatal complications through hematogenous spread or direct extension: 1

• Septic jugular vein thrombophlebitis (Lemierre syndrome) 1
• Descending mediastinitis - occurs in approximately 7% of cases and requires combined cervical and thoracic surgical drainage 1, 4
• Bacterial endocarditis 1
• Intracranial abscess 1
• Airway obstruction - requiring emergency tracheostomy in 5-21% of cases 2, 4
• Sepsis 2, 4

Microbiology

The bacteriology reflects the source of infection: 1

• Odontogenic infections: Mixed aerobic and anaerobic flora including Streptococcus species, Peptostreptococcus, Streptococcus viridans, Streptococcus intermedius and constellatus 1, 2, 3

• Oropharyngeal infections: Occasionally involve mycobacteria, staphylococci, and gram-negative bacilli 1

• Exogenous infections: Predominantly gram-negative bacilli and staphylococci 1

Streptococcus and Staphylococcus are cultured in approximately 50% of cases. 2

High-Risk Populations

Certain patient populations face significantly higher morbidity and mortality: 2

• Diabetic patients (present in 10.5% of cases) 2
• Immunocompromised patients 2
• Elderly patients 2
• Patients with involvement of four or more neck spaces (15-fold increased risk of requiring repeat surgical drainage) 5
• Patients with elevated blood glucose levels 5

Clinical Pitfalls

Critical diagnostic considerations to avoid delays in treatment: 1

• Avoid swabbing the epiglottis in suspected epiglottitis - blood cultures are the preferred diagnostic method 1
• Swabs are inadequate specimens - obtain aspirates, tissue biopsies, or fluid from affected tissues while avoiding contamination with mucosal flora 1
• Use anaerobic transport containers as both aerobic and anaerobic bacteria survive in anaerobic transport 1
• Spirochetes involved in odontogenic infections cannot be recovered in routine anaerobic cultures but will be visible on Gram stain 1
• Request Gram-stained smears for all anaerobic cultures to evaluate specimen adequacy, provide early presumptive diagnosis, and identify mixed infections 1