Ludwig's angina is a serious,
potentially life-threatening infection of the floor of the mouth.
It is a type of phlegmonous infection of the soft tissue involving the floor of the mouth that rapidly extends bilaterally to the soft tissues of the oral cavity and neck. It involves 2 compartments on the floor of the mouth including the sublingual and submandibular space bilaterally.
Wilhelm Friedrich von Ludwig first described this condition in 1836.
Knowledge of neck anatomy is basic to understanding the clinical manifestations,
pathogenesis,
progression,
and complications of Ludwig angina.
The mandibular space lies above the hyoid bone.
It is subdivided into two compartments by the mylohyoid muscle: the sublingual space,
located between the oral mucosa and the mylohyoid muscle,
and the submandibular space,
located between the mylohyoid muscle and the skin and superficial fascia .
There is communication between these two spaces around the posterior free border of the mylohyoid muscle.
Infection in the mandibular space may subsequently spread into adjacent areas including the pterygomandibular,
masseteric,
and temporal spaces
Grodinsky,
in 1939,
established strict criteria that are still used to establish the diagnosis of Ludwig angina.
The criteria define Ludwig angina as a cellulitis,
not a focal abscess,
of the mandibular space that: 1) always involves both the sublingual and submandibular spaces and is almost always bilateral,
2) produces gangrene or serosanguinous phlegmon but little or no frank pus;3) involves connective tissue,
fascia,
and muscles,
but not glandular structures; and 4) is spread by contiguity,
not by lymphatics.
The infection is odontogenic in an estimated 90% of cases but also may result from penetrating trauma.
Ludwig's angina usually affects patients between 20 and 50 years.
It is most commonly seen in patients with an odontogenic infection involving the second and third mandibular molars,
because these tooth apices extend inferiorly to the mandibular insertion of the mylohyoid muscle,
thus allowing direct extension of infection into the submandibular space.
From there,
infection may spread into other fascial spaces of the neck and may lead to airway compromise and mediastinitis.
The infection may spread even parapharyngeal and retropharyngeal spaces.
Its gravity is that may compromise the airway.
Predisposing factors include poor dental hygiene,
dental caries,
trauma,
malnutrition,
alcoholism diabetes,
lupus erythematosus,
neutropenia,
compromised immune status,
and intravenous drug abuse.
However,
Ludwig angina may occur in children without any known predisposition.
Ludwig’s angina is predominantly caused by bacteria from the oral cavity flora since the majority of the cases are caused by dental infections.
Bacteriologic study usually shows a polymicrobial involvement,
being the most frequent bacteria: alpha hemolytic Streptococcus,
Staphylococcus aureus,
Bacteroides and Haemophilus influenzae.
The combination of aerobic and anaerobic organisms has a synergistic effect due to production of endotoxins that contribute to the rapidly spreading cellulitis.