Overview 

Ludwing’s angina(LA) is a serious life threatening condition in which there is infection spreading into the deeper layer of the skin called cellulitis. It usually affects the floor of the mouth, submandibular region and also neck area. Based on the severity it can cause airway obstruction and can even lead to death of the individual, so there is a need for immediate medical attention. The origin of the infection is the mouth (oral cavity) caused by bacteria. The individuals having poor oral hygiene and low immunity are most prone to this cellulitis. Most of the patients may end up in intensive care units (ICU), and if diagnosis and treatment are done at the right time, Ludwig's angina can be prevented. There are many predisposing conditions that lead to rapid advancement of LA such as poor oral hygiene, diabetes mellitus, malnutrition, alcohol related disorders, immunosuppression such as AIDS, and organ transplant recipients. Even though antibiotics have effectively reduced the morbidity and mortality, patients with these conditions should be treated more cautiously. 

Clinical course of the infection

There are fascial spaces in the head and neck region that are usually not evident as the spaces are filled with loose connective tissue. If there is any spread of infection, these spaces can become evident as there is a breakdown in the connective tissue. They are bounded by anatomical boundaries like bone, muscle, or even fascial layers.

Figure 1- shows the various fascial spaces of the face. The picture shows canine space, buccal space, masticatory space, parotid space, and infratemporal space. The inset shows the space infection top right-canine space infection and bottom left shows masseteric space infection.

There are different classifications of fascial spaces. Broad classification into primary and secondary. Primary fascial spaces are directly linked with the oral cavity, and secondary is not directly related, but the infection of the primary leads to the secondary fascial space infection. In Figure 1, the fascial spaces of the face are depicted and in Ludwig's angina mostly bilateral submandibular, sublingual, and submental spaces are affected, which comes under the suprahyoid fascial spaces.³

Figure 2- fascial spaces involved in Ludwig's angina are mostly bilateral submandibular, sublingual, and submental spaces. 

Ludwig's angina initiates when there is an infection, usually a dental infection in the floor of the mouth, and rapidly extends to the submandibular space, eventually to the submental and sublingual space. Obstruction of these fascial spaces can lead to enlargement as well as elevation of the tongue, which may obstruct the airway. If the infection is untreated, it may also lead to swelling (oedema) of the structure of the airway. It can spread to other spaces in the neck, and the appearance is known as a bull neck. It is an alarming condition that needs emergency intervention and if left untreated can lead to the death of the individual.⁴

Figure 3- The infection can cause enlargement of fascial spaces, pushes and elevates the tongue, and causes airway obstruction.

Risk factors and predisposing conditions

Dental infections are the most common cause of infection, usually back teeth (molars). It can also be caused by oral piercing or cut (laceration), mandibular fracture, dental extraction, traumatic intubation, osteomyelitis, peritonsillar abscess, submandibular sialadenitis, otitis media, and infected thyroglossal cysts. Other predisposing factors are poor oral hygiene, diabetes mellitus, malnutrition, alcohol related disorders, immunosuppression such as AIDS, and organ transplant recipients.^4,5

The causative organisms that are related to a streptococcus species group, and other species that are related to infections are staphylococcus, fusobacterium, and bacteroides. In immunocompromised patients, atypical organisms such as pseudomonas, E coli, candida, and clostridium species are also noted. Pus formation is very limited.⁶ Patients with diabetes, hemodialysis, and recent hospitalisation (within a year) are at an increased risk of methicillin-resistant Staphylococcus aureus (MRSA) infection.

Common immunocompromised states associated with LA

Diabetes Mellitus (DM)

It is always a known fact that diabetes may lead to more susceptibility to infections and this may engender subsequent mortality. Many studies have found that there is a drastic decrease in innate immunity in DM patients, with notable effects on the functions of polymorphonuclear cells; a category of white blood cells that will decrease the ability to fight infections.^6,7

HIV/AIDS

Human immunodeficiency virus(HIV) usually affects the defence mechanism, especially CD4T cells, which are an integral part of our immune system. This immunocompromised state can lead to LA and can cause airway obstruction at an accelerated pace.⁸

Chemotherapy / Oncology patients

Chemotherapy is often associated with multiple side effects that alter the quality of life. Chemotherapy can lead to a decreased white blood cells that cause immunosuppression. It also causes mucositis, and osteoradionecrosis; these can lead to a spread of infection. So proper hygiene should be maintained, and these oral complications should be treated immediately. No dental treatments should be performed during chemotherapy such as extraction, scaling, and root planing as even a minor cut can cause infection.⁹

Post-organ transplant and immunosuppressive therapy

Immunosuppressive drugs are often prescribed to patients who receive an organ transplant to decrease the risk of rejection of the new organ by the immune system. It lowers our immunity, leading to a high risk of infection.¹⁰

Management strategies

Immunocompromised individuals are more likely to develop LA, which progresses rapidly and becomes the cause of mortality. The infection from the submandibular and sublingual gland may spread to the surrounding tissue spaces, which can lead to potential complications such as airway obstruction, aspiration pneumonia, carotid sheath abscess, sepsis, and mediastinitis. Therefore, complications in immunocompromised individuals should be managed promptly with airway correction, either by intubation or cricothyrotomy. Administering broad spectrum antibiotics can be a life-saving treatment, and if needed, surgical treatment should be carried out. Frequent monitoring is needed for such individuals. If the patient is diabetic, the blood glucose level should be maintained.¹¹

FAQs

What are the important signs of LA?

There are mainly 4 signs

• Bilateral Involvement of more than single tissue spaces
• Serosanguinous, putrid infiltration, but little or no pus
• Involvement of connective tissue, fascia, but not glandular structures
• Spread via fascial spaces continuity not by lymphatic system

Most common symptoms of LA in the early stage?

Fever, tiredness, inability to swallow saliva, difficulty to open the mouth, and difficulty to move the tongue.

What is the extreme complication of LA?

• Asphyxiation (lack of oxygen)
• Aspiration pneumonia (lung infection)
• Blocked airway
• Mediastinitis (infection to the chest)
• Sepsis 
• Septic shock

How is LA diagnosed?

It is usually identified by physical examination, and by examining the oral cavity the root cause may be identified. Bacterial cell culture obtains the strain of bacteria involved, computed tomography, and magnetic resonance imaging. 

How quickly can LA develop?

It can develop quickly within half an hour of infection, and the condition can get worse. So if severe symptoms develop, seek immediate medical attention.

Summary

LA is a potentially life-threatening infection caused mainly by bacteria. The discovery of antibiotics and good oral hygiene practices have reduced the likelihood of the disease. Potential immunocompromised states such as DM, HIV, chemotherapy, and organ transplantation has increased the chances of LA. Good foundational understanding and training should be given to physicians regarding the life-threatening condition. Furthermore, the general public should also be aware of such situations, as these conditions can deteriorate at an alarming pace. Airway obstruction is usually the cause of death, and maintaining a patent airway should be the primary goal in the treatment.