Introduction

Ludwig's angina is a type of progressive cellulitis that invades the floor of the mouth and soft tissues of the neck. Most cases result from odontogenic infections which spread into the submandibular space.

It is a life-threatening emergency as airway obstruction can occur rapidly as a result. Urgent medical treatment and airway assessment is required.

Epidemiology

  • Incidence: 0.50 cases per 100,000 person-years
  • Peak incidence: 40-50 years
  • Sex ratio: 1:1
Condition Relative
incidence
Peritonsillar abscess (quinsy)60.00
Ludwig's angina1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Aetiology

Over 70% of cases occur as a result of dental infections, particularly from the second or third mandibular molars. Less common causes include:
  • Peritonsillar abscesses
  • Mandibular fractures
  • Oral lacerations/piercings
  • Sialadenitis
  • Oral malignancy

Predisposing factors include:
  • Dental cavities
  • Previous dental procedures
  • Systemic conditions:
    • Diabetes mellitus
    • Malnutrition
    • Alcoholism
    • AIDS
    • Other immunosuppressive conditions

Pathophysiology

Ludwig's angina occurs when infection from a nearby source spreads contiguously into the sublingual and submandibular space. It can then progress rapidly and travel to the parapharyngeal and retropharyngeal spaces, encircling the airway.

Infections are typically polymicrobial and can involve various species of oral flora which arise from odontogenic sources. The most commonly isolated pathogens are:
  • Streptococcus viridans
  • Staphylococcus aureus
  • Staphylococcus epidermidis
  • Peptostreptococcus spp.
  • Bacteroides spp.
  • Fusobacterium spp.
In immunocompromised patients gram negative aerobes such as Pseudomonas aeruginosa may also be involved.

Clinical features

Most patients report neck swelling often with either dental pain or following a recent dental procedure. Clinical features can evolve rapidly as the infection spreads and other potential symptoms include:
  • Dysphagia (35%)
  • Pharyngodynia (25%)
  • Fever (25%)
  • Trismus (15%)
  • Dysphonia (15%)

Signs on physical examination include:
  • Bilateral submandibular swelling
  • Elevated or protruding tongue
  • Signs of respiratory distress if airway compromise is already present
    • Dyspnoea (15%)
    • Tachypnoea
    • Stridor

Investigations

Ludwig's angina is a clinical diagnosis and investigations should not delay initial management. However, the following bloods should be taken:
  • FBC
    • Leukocytosis
  • CRP
  • Blood cultures
    • To assess for haematogenous spread

Microbial culture and analysis can be attempted
  • Needle aspiration of submandibular space
    • Often unsuccessful in the absence of abscess formation.

It may also be useful to obtain imaging:
  • CT scan with IV contrast
    • To identify suppurative complications that require surgical drainage or if the diagnosis is unclear.
  • Dental X-ray
    • To identify the potential source of infection.

Differential diagnosis

Ludwig's angina may present similarly to other infectious neck masses and is frequently found in combination with other deep space neck infections. As these can all present with the similar clinical features of neck swelling, fever and sore throat they can often only be differentiated by the precise location of the swelling. A CT scan of the neck can be useful if the diagnosis is unclear. Examples include:
  • Peritonsillar abscess
    • Uvular deviation, trismus
  • Retropharyngeal abscess
    • Bulging of pharyngeal wall
  • Acute suppurative parotitis
    • Unilateral induration from cheek to jaw

It is also important to rule out non-infectious causes of neck swelling:
  • Oral carcinoma
    • Persistent oral ulcerations, cervical lymphadenopathy, weight loss?
  • Angioedema
    • History of allergies or ACE inhibitor use? Swelling and hives in other parts of the body?
  • Submandibular haematoma
    • History of trauma and anticoagulation?

Management

Initial treatment consists of urgent airway assessment and management combined with broad-spectrum intravenous antibiotics.

There are no specific guidelines for the treatment of Ludwig's angina, however, the following principles are based on retrospective studies and UpToDate recommendations:
  • Admission to a high dependency unit (HDU) or ENT ward with close airway observation.
  • If respiratory distress is present, immediate intubation or tracheostomy may be necessary.
    • Fibreoptic laryngoscopy is useful for airway assessment and assisting intubation.
  • Empiric antibiotic regimens with coverage for beta-lactamase producing gram-positive, gram-negative, and anaerobic organisms are advised. However, there are no clinical trials to date to support any particular regimen.
    • Options include combinations of ampicillin-sulbactam, clindamycin, and metronidazole.
  • If the patient is immunocompromised antibiotic treatment should be extended to involve anti-pseudomonal coverage and vancomycin should be considered if there is an increased risk of MRSA.
  • Antibiotics should be continued intravenously for a duration of two to three weeks.
  • Surgical drainage should be performed to treat localised abscesses or following failure of medical management.
  • If an infected tooth is determined as the source, it should be extracted.

Complications

Airway obstruction is the most common serious complication and can develop rapidly at any stage. It can lead to either:
  • Asphyxia
    • The most common cause of death.
  • Aspiration pneumonia

Other major complications in descending order of frequency include:
  • Septicaemia
    • Blood cultures should always be taken.
  • Mediastinitis
    • Due to spread through the retropharyngeal space and into the superior mediastinum.
    • Can be identified using a chest X-ray.
  • Cervical necrotizing fasciitis