Ludwig's angina is a potentially life-threatening infection of the submandibular, sublingual and submental spaces. It was first described by Wilhelm Friedrich von Ludwig, a German physician, in 1836, as a gangrenous induration of the soft tissues of the floor of the mouth and neck, with a ‘woody’ cellulitis (Winters, 2003). Peak incidence of the disease occurs between the ages of 20 and 40 years, predominantly in men (McMorran et al, 2019). There are many predisposing factors that are thought to place patients at an increased risk of developing the condition. These include recent dental treatment, dental caries or generally poor dentition, chronic disease such as diabetes, alcoholism, malnutrition, and a compromised immune system such as people with AIDS or following organ transplantation (Candamourty et al, 2012).
Since the introduction of antibiotics in the 1940s, with advances in surgical approaches and improved oral and dental hygiene, the mortality rate for Ludwig's angina, which once exceeded 50%, has reduced significantly (Saifeldeen and Evans, 2004; Lai and Pancer, 2018). By the 1990s, mortality rates were down to 10% or lower (Kurien et al, 1997; Neff et al, 1999). However, although they are now rare, deep neck infections are still potentially fatal (Furst et al, 2001; Boscolo-Rizzo and Da Mosto, 2009). Reviews of deep space neck infections have estimated the incidence of Ludwig's angina at between 4% (Srirompotong and Art-Smart, 2003) and 8% (Eftekharian et al, 2009). This drop in mortality and incidence is due to advances in both preventive and curative health care but it has now left many health professionals with increasingly limited experience of Ludwig's angina (Saifeldeen and Evans, 2004). Because it can rapidly deteriorate without immediate and adequate treatment, this now limited experience could increase the risk to patients, if a timely diagnosis is not given.
A small study carried out by Srirompotong and Art-Smart (2003) suggested that Ludwig's angina is up to 90% odontogenic in origin. The erosion of enamel allows the introduction of bacteria into the tooth, triggering the most common cause, dental caries. These bacteria may spread first into the pulp then to the root and local tissues producing gingivitis or dental abscesses. Retropharyngeal abscess or Ludwig's angina may result when this infection spreads to the deep fascial planes (Connolly and Rankin, 2017).
Common sources of infection relate to dental procedures involving the second and third molars, because the roots of these molars provide a direct route into the mandibular space as they extend into the mylohyoid muscle (Srirompotong and Art-Smart, 2003).
Case study
Mr Jones (a pseudonym has been used), a 46-year-old male, entered the out-of-hours streaming area of the local emergency department (ED), presenting with a 3-day history of general lethargy and fever, and a significant, rapid onset of tender, bilateral submandibular swelling, drooling saliva and trismus. On taking a clinical history, it was noted that Mr Jones had recently suffered dental pain, which he had left untreated, accompanied by a 10-day history of throat discomfort. His observations on arrival showed pyrexia of 38.6°C, heart rate of 122 beats per minute, respiratory rate of 22 breaths per minute, blood pressure 146/88 mmHg, and oxygen saturations on air 96% rising to 99% on 15 litres free-flow oxygen. Although oxygen saturations on arrival were deemed within the lower end of normal limits, in view of the red flag signs of bilateral submandibular swelling, drooling saliva and trismus, oxygen was administered in case of sudden loss of airway. Airway compromise is the leading cause of death in Ludwig's angina (Pak et al, 2017) and airway protection is the foundation of treatment (Hassan et al, 2011). On examination, there was no notable use of accessory muscles, which is an indication of difficulty in breathing (Innes et al, 2018), and the patient's breathing pattern appeared normal, with no stridor or dyspnoea detected.
Dysphonia was evident during the history-taking process, with Mr Jones's daughter affirming that his voice appeared notably distorted. Mr Jones confirmed that he had not visited his dentist for ‘a few years’, because he had not noticed any significant dental issues. Shortly after his dental pain started, he attempted to attend his dental practice but discovered he had been removed from the registered patient list due to a lack of attendance. He was aware that he had dental caries but sought no further help or advice regarding this until self-presenting to the ED, with submandibular swelling. This swelling was bilateral in presentation and was affecting more than one deep tissue space of the neck.
Anatomy
The cervical fascia of the head and neck offer minimal resistance to infection, which can have extremely serious implications for patients. The structure formed by the fascial planes contains at least 11 deep spaces offering potential infection sites. There are the spaces located above the hyoid bone level: peritonsillar, submandibular, parapharyngeal, buccal, parotid and temporal. There are also spaces that fully encompass the circumference of the neck, including retropharyngeal, prevertebral and carotid; and the anterior visceral space below the hyoid level (Kataria et al, 2015).
There are three severe potential complications related to lateral pharyngeal space infections. The first is internal jugular vein thrombosis. The second is erosion into the carotid artery and the third is cranial nerve interference, in particular nerves 9-12 and the sympathetic chain (Shemesh et al, 2019).
Causes of Ludwig's angina
Although dental infection is often a primary cause of Ludwig's angina, clinicians must also be aware of other potential causes, which include peritonsillar abscesses, oral lacerations, open mandibular fractures, submandibular sialadenitis (infection of the salivary glands), and tongue piercings (Srirompotong and Art-Smart, 2003). The bacteriology of Ludwig's angina is poly-microbial and mainly involves the oral flora. The most frequently isolated organisms in patients with the condition are Streptococcus viridans and Staphylococcus aureus. Anaerobes are also frequently involved, including Bacteroides, Peptostreptococcus and Peptococcus (Lemonick, 2002).
Inflammatory response
Inflammation may be explained by considering the complement, kinin and clotting systems. Twenty different proteins are involved in the complement system, and these various chemicals act as a cascade, each one setting off another in the sequence involved in protecting the body against invading microbial agents. The overall results increase vascular permeability, promote chemotaxis, engulf invading microorganisms and, through a process called lysis, destroy pathogens. Bradykinin is a chemical substance released by the kinin system. It causes smooth muscle tissue to contract and blood vessels to dilate and may result in pain. Like the complement system, the clotting system forms a cascade of 13 different chemicals resulting in the formation of blood clots, increased vascular permeability and the promotion of chemotaxis for white blood cells. Acute inflammation also involves other substances such as prostaglandins and leukotrienes. Prostaglandins are derived from the membranes of most cells, and are accountable for pain, fever and further vasodilation. Leukotrienes, which are found in mast cells, promote vascular leakage but not chemotaxis, and cause white blood cells to adhere to damaged tissues, speeding the removal of bacteria and promoting healing (Fallon and Fleming, 2014).
The release and actions of these chemicals during the acute phase of inflammation are responsible for the classical signs of inflammation displayed by Mr Jones, including fever and the swelling and tenderness to the floor of his mouth and submandibular region. These reactions also offer an explanation for the dysphonia Mr Jones was experiencing.
Vocal sound and dysphonia
Air passing through the open glottis produces sound waves by vibrating the vocal folds. It is the diameter, length, and tension of these folds, on which the pitch of the sound depends. The diameter and length are related to the size of a person's larynx, and contracting voluntary muscles, which reposition the arytenoid cartilages relative to the thyroid cartilage, control the tension. The pitch rises when this distance increases and vocal folds tense. When the distance decreases, vocal folds relax and the pitch lowers. Articulation is the modification of these sounds by other structures such as teeth, tongue and lips to form comprehensible sounds (Martini et al, 2015).
In Mr Jones's case, the gross swelling of the floor of the mouth, resulting in the lifting and expulsion of his tongue, accompanied by possible swelling further into his larynx, explains his dysphonia, and highlighted a significant potential risk to his airway (Lai and Pancer, 2018; Pak et al, 2017). Airway obstruction is the most life-threatening complication of this condition due to the progressive swelling of the soft tissues, accompanied by the elevation and posterior displacement of the tongue (Candamourty et al, 2012).
There are three key areas to the management of Ludwig's angina. First, the maintenance of an effective airway, second, aggressive antibiotic therapy and, third, decompression of the submandibular, sublingual and submental spaces as required by surgical intervention (Winters, 2003).
Conservative approach to treatment
A conservative approach to the management of Ludwig's angina has been encouraged for appropriate patients, over the conventional aggressive airway management strategies previously favoured. This includes intravenous (IV) antibiotic therapy, close airway observations and the drainage of any collectable abscess (Hasan et al, 2011). In such cases, patients should be admitted to a high-dependency setting for continuous airway monitoring. These patients may decompensate rapidly, developing complications including aspiration, pneumonia, empyema, mediastinitis, pericarditis, carotid artery or internal jugular vein thrombosis or erosion, and sepsis (Filippone, 2004). A recent article comparing outcomes of conservative treatment with surgical treatment for Ludwig's angina concluded that there was a higher incidence of airway compromise in the conservative treatment approach (Edetanlen and Saheeb, 2018).
Airway management
For all patients presenting with this condition, airway management is the key priority (Lai and Pancer, 2018; Shemesh et al, 2019). However, there appears to be a distinct lack of any formal guidelines for airway control for this patient group, perhaps reflecting little recent research into the condition. The decision to secure the airway is still largely based on the clinical judgment and experience of the attending clinician. Due to the potential for bleeding and abscess rupture, blind nasotracheal intubation should be avoided in patients with Ludwig's angina. More favoured techniques include orotracheal intubation or fibre-optic-guided nasotracheal intubation. The main priority is to recognise symptoms of respiratory distress and impending airway obstruction, because this would require immediate intubation (Winters, 2007). In this case study, the patient's inability to swallow, as shown by drooling, suggested that airway obstruction might be imminent (Lai and Pancer, 2018). A tracheostomy under local anaesthetic is considered the ‘gold standard’ of airway management in patients with Ludwig's angina. This may, however, be difficult in patients presenting with advanced onset of infection due to the anatomical distortion of the anterior neck (Candamourty et al, 2012) and, as discussed, the more conservative approaches are now encouraged as first-line treatment.
In Mr Jones's case, he was assessed as having a stable airway on arrival at the ED. He was therefore managed conservatively with extremely close monitoring in the ‘resuscitation’ area of the department. He was placed on 15-litre high-flow oxygen therapy via a face mask, placed into an upright-seated position on the trolley with continuous cardiac and oxygen saturation monitoring, and IV metronidazole (500 mg) was started (Edetanlen and Saheeb, 2018). At this point, consideration was given to Mr Jones's observations. He was experiencing tachycardia, tachypnoea, and pyrexia. These observations, accompanied by the history of acute deterioration of functional ability, placed Mr Jones at moderate to high risk of sepsis (as outlined on the National Institute for Health and Care Excellence (2017) stratification tool). Arterial blood gases, including lactate, and blood cultures were taken for analysis, accompanied by other laboratory blood tests, including full blood count, urea and electrolytes, liver function tests and a blood glucose level.
Small or particularly deep abscesses in the neck cannot always be identified by ultrasonography, nor does this method of investigation provide the detailed anatomical information required for surgical intervention. Therefore, contrast-enhanced CT is the method of choice in radiological evaluation of deep neck infections (Celakovsky et al, 2014). A CT scan was arranged, and the anaesthetist contacted the ear, nose and throat (ENT) consultant for immediate review. Mr Jones was then transferred to the high-dependency unit for continued airway monitoring, while his CT report was analysed and a more formal and detailed plan of care was considered.
Differentials and diagnosis
The investigations confirmed the diagnosis of Ludwig's angina. In this case, it was the detailed history taking, and obvious significant bilateral submandibular swelling, accompanied by dysphonia, that led an experienced nurse practitioner to raise concerns regarding the possibility of Ludwig's angina with both efficiency and certainty, ensuring the best possible outcome for Mr Jones. There are, however, several potential differential diagnoses to consider when assessing a patient presenting with symptoms such as those displayed by Mr Jones. These include angioneurotic oedema, cellulitis, lingual carcinoma, lymphadenitis, peritonsillar abscess, salivary gland abscess and sublingual haematoma (Lemonick, 2002). Due to the rapid and potentially life-threatening spread of this condition, early diagnosis and interventions are essential to maximise an optimum outcome for patients.
Four criteria have been proposed to aid in this process and distinguish Ludwig's angina from other forms of deep neck abscesses. The infection must:
Any patient presenting with symptoms such as those displayed by Mr Jones should be treated as a case of Ludwig's angina, until proven otherwise. In this case, the other differential diagnoses discussed were ruled out when Mr Jones's symptoms were considered against the four criteria noted, and the imaging results were analysed.
Importance of communication
During the rapid assessment, monitoring, stabilisation, and treatment initiation, effective communication was important not only in liaising between health professionals in the department, but also explaining procedures and options to Mr Jones and his daughter throughout. When Compassion in Practice launched the ‘6 Cs’ of nursing in 2012, it offered the opportunity to reinforce sometimes forgotten values and beliefs that should underpin nursing care wherever it takes place (Cummings and Bennett, 2012). Care, compassion, competence, communication, courage and commitment are all values and behaviours that should be held in equally high regard by nurses today. When providing care for Mr Jones and his daughter, consideration was given to all these values. Each stage of the process was explained, and each question was met with compassion and care. Compassion in Practice highlighted communication as central to successful caring relationships and to effective team working—it provides benefits for those receiving care and staff alike (Cummings and Bennett, 2012; Health Education England, 2017). Listening is as important as what is said and done and essential for the principle of ‘no decision about me without me’.
Dental problems in the context of the emergency department
In one UK study it was shown that dental problems were the second most common reason, after drug interactions, that patients telephoned the ED seeking advice (Crouch et al, 1996). Studies also revealed that the aetiology of Ludwig's angina in patients presenting to hospital was odontogenic in origin (Samaei et al, 2015; Botha et al, 2015; Pak et al, 2017; McDonnough et al, 2019). These presenting complaints should give rise to consideration that a patient may be presenting with symptoms of the potentially life-threatening condition of Ludwig's angina, and yet Nasr et al (2013) highlighted that only 6% of ED medical staff in England had received any dental training in medical school.
In 2015, a UK survey found that 13% of men and 8% of women reported not attending a dentist in the previous 5 years, instead presenting their oral health concerns to their GP (Ahluwalia et al, 2016). The British Dental Association (BDA) has said that patients accessing EDs with dental complaints could be costing the NHS as much as £18 million a year. It also estimated that approximately 600 000 patients a year are seeking treatment from primary care practitioners who, like ED clinicians, are not equipped to treat dental pain (Newcastle University Press Office, 2017). This highlights the need for not only ED clinicians, but also GPs and advanced nurse practitioners to recognise the signs and symptoms of dental emergencies such as Ludwig's angina, and provide prompt emergency care to facilitate the best possible outcomes for their patients.
There is a great deal of uncertainty regarding the future of the NHS in the UK at present, and many issues should be taken into consideration when discussing patient's expectations and the appropriateness of their access to health care. Poverty is associated with an increase in oral infections. People of a lower socio-economic group are found to be more likely to smoke, have more sugar in their diet, and delay attending dental services due to requirements to pay (Wingfield, 2015). These factors may all play a part in increased presentations of dental abscesses.
‘The poorest people with the greatest burden of disease are the very same people who have the worst access to dental healthcare—the inverse care law applies as much to teeth and gums as to any other part of the body.’
If more in-hours urgent care appointments were commissioned, the BDA believes that dentists could play a significant part in easing the ever-increasing demands on EDs across the UK. It has been put forward to the Chief Dental Officer for England that if the BDA's proposal to accomplish this were achieved, it would also have the benefit of offering clear guidelines to the NHS 111 service as to which emergency dental care services have the capacity to treat patients (BDA, 2017).
Conclusion
Ludwig's angina is a potentially life-threatening, rapidly expanding, diffuse inflammation of the submandibular and sublingual space. Progressive oedema of the tongue, inflammation of the pharynx and inflammatory distension of the fascial planes of the neck can lead to respiratory tract obstruction and death (Srirompotong and Art-Smart, 2003; Edetanlen and Sahee, 2018; Lai and Pancer, 2018).
Although it may be suggested that dental issues should not be a focus for advanced clinical practitioners (ACPs), the concerning statistics have shown that, even though general practice and the ED may not be the most appropriate place for these patients to present, this is, in fact, where they are attending. Clinicians must therefore be trained, and prepared to deal with each case appropriately, by being confident to refer patients back to their own dentist for either a routine or urgent appointment, liaise with specialists to consider more unusual or advanced presentations or, in certain instances, such as Mr Jones's case, initiate immediate, potentially life-saving treatment.
Patients with dental problems frequently present to the ED at weekends and outside normal working hours, when dentists may not be available to offer appointments. An adequate understanding of dental disease and trauma is therefore imperative for clinicians to be able to diagnose, treat and refer patients with dental emergences efficiently (Samaei et al, 2015). Although advanced nurse practitioners have a limited role in the treatment of Ludwig's angina, their ability to promptly recognise the signs and symptoms of this condition, and therefore initiate prompt emergency care and treatment, will facilitate better outcomes for their patients (Winters, 2003).
In Mr Jones's case, early diagnosis from an experienced nurse practitioner, and rapid involvement of the multidisciplinary team were imperative to ensure a safe outcome. This highlights the need for ongoing education and awareness as they are crucial for the successful diagnosis, management and treatment of this potentially life-threatening condition (Pak et al, 2017). Early diagnosis, aggressive antibiotic therapy, and management involving a multidisciplinary team approach are imperative for these patients to progress without complications (Winters, 2003).