Ludwig's Angina or Ludovici's Angina is acute inflammation in the form of progressive diffuse cellulitis or phlegmon of the sublingual, submental, and submandibular spaces on the floor of the mouth. Swelling of the submandibular cavity and causing tongue elevation, which can lead to airway obstruction. The obstruction causes a choking sensation and shortness of breath (angina).

Ludwig's Angina: Definition, Etiology, and Risk Factors
Swelling in the submandibular area in a patient with Ludwig's angina 
(pointed by a red arrow)

Karl Friedrich Wilhelm von Ludwig first discovered this disease in 1836. He made observations on five patients and found gangrene that formed induration in the neck's soft tissue, which then involved the connective tissue surrounding the muscles between the larynx and floor of the mouth.

According to Lemonick (2002), this disease includes odontogenic infectious diseases, in which bacterial infections originate from the oral cavity. The specific characteristic that distinguishes Ludwig's angina from other oral infections is the involved mouth's floor and the two submandibular spaces (sublingual and submaxillary).

Etiology and Risk Factors

a. Etiology

What causes Ludwig's angina? Ludwig's angina is usually preceded by a mild infection, which then spreads and forms an induration in the upper neck. Then form an abscess in the submandibular, sublingual, and submental cavities.

The most common etiology of Angina Ludwig is the infection of the lower third molar. But it can also occur due to the suppurative process of the cervical lymphatic node in the submaxillary space.

The most often causative agent for Angina Ludwig is the combination of aerobic and anaerobic bacteria. Some of the bacteria reported causing Ludwig's Angina are Streptococcus viridans, Staphylococcus aureus, and Staphylococcus epidermidis.

At a lower frequency, about 7%, Angina Ludwig, is reported due to Group A Streptococcus beta-hemolytic bacteria. Some of the other infectious agents that have been reported to cause Ludwig's Angina are Bacteroides, Fusobacterium nucleatum, Peptostreptococcus, and Enterobacter aerogenes.

Several studies have reported the existence of rarer organisms that can cause Angina Ludwig, such as Proteus, Pseudomonas, Escherichia coli, Haemophilus influenzae, Neisseria catarrhalis, Borrelia vincenti, and Morganella morganii. Candida albicans fungal infection has also been reported in some literature, especially in immunocompromised patients.

Other causes of Ludwig's angina are:
  • sialadenitis, 
  • peritonsillar abscess, 
  • open mandibular fracture, 
  • infected thyroglossal duct cyst, 
  • epiglottitis, 
  • intravenous injection of the drug into the neck, 
  • traumatic bronchoscopy, 
  • endotracheal intubation, 
  • oral laceration, tongue piercing, 
  • upper respiratory tract infection, 
  • and trauma to the floor of the mouth.

b. Risk Factors

The risk factors for Angina Ludwig are mainly conditions that allow the infection to occur easily, such as poor oral hygiene, dentinal caries, diabetes mellitus, intravenous drug abuse, and alcoholism. Poor oral hygiene is found in 75-95% of cases.

Patients with immunocompromised such as long-term steroid use, HIV infection, and malnutrition can also make the infection more prone. Patients with malignancy of the oral cavity may also predispose to Ludwig's Angina.

The presence of infection and trauma to the face can predispose to Ludwig's Angina. 

Infections :
  • peritonsillar abscess, 
  • osteomyelitis, 
  • submandibular sialadenitis, 
  • and thyroglossal cysts 

Facial trauma : 
  • mandibular trauma and lacerations in the oral cavity also increase the susceptibility to infection of the soft tissues inside the neck.