Facial cellulitis and Ludwig's angina: why they need hospital treatment

A dental infection starts at the tip of a root or in the gum, and the pus first collects inside the bone. When this pus breaks through the bone into the soft tissue, it takes one of two routes. Either it collects inside a pocket and forms an abscess with clear edges, whose centre sometimes feels fluctuant when pressed with a finger; or it spreads into the spaces between muscle and fat without forming a pocket. The second is called cellulitis. In cellulitis there is not yet a pocket of pus in the tissue to drain; the whole area is swollen with inflammatory fluid, hard and hot. The NHS describes cellulitis in general as an infection in which the skin is painful, hot and swollen and you may feel unwell, as if you have flu, and writes that if it is not treated quickly the infection can spread to the blood, muscles and bones.

This distinction matters because it changes the treatment. With a contained abscess, the dentist drains the pocket and deals with the source; hospital is usually not needed. With cellulitis, however, there is no single pocket to drain, and depending on which way it moves, the infection can pass into the interconnected spaces of the face and neck. These spaces, reaching round the eye, the throat, the floor of the mouth and from there into the neck, allow the infection to get close to the airway and the inside of the skull. That is why spreading cellulitis is treated in hospital, with intravenous antibiotics, imaging, surgical drainage when needed and close monitoring of the airway.

Ludwig's angina is the form this takes in the floor of the mouth. MSD Manuals defines it as a rapidly spreading, bilateral, hardened cellulitis of the soft tissues under the jaw, the floor of the mouth and both the sublingual and submandibular spaces; it adds that no abscess forms, but that it resembles an abscess and is treated in a similar way. The source is usually a dental infection, particularly of the lower second and third molars. Poor oral hygiene, tooth extraction and a fracture of the lower jaw or injuries to the floor of the mouth are also among the predisposing factors.

The picture MSD describes develops like this: first, pain in the affected teeth and a very tender, localised hardness under the chin and under the tongue. Then board-like hardness of the floor of the mouth and a thick, hard swelling of the tissues over the hyoid bone can develop quickly. Drooling, being unable to open the mouth, difficulty swallowing, noisy breathing caused by swelling of the larynx (stridor) and the back of the tongue being pushed up towards the palate can be seen. A fever, chills and a fast pulse usually come with it. MSD stresses that this condition can block the airway within hours, and that it does so more often than other neck infections.

An evidence-based review written for emergency doctors turns a sign people often wait for on its head: in Ludwig's angina, being unable to open the mouth is a late finding. In other words, still being able to open your mouth does not show that the condition is mild; if there is hardness in the floor of the mouth and swelling under both sides of the jaw, an urgent assessment is needed even before mouth opening becomes restricted. The same review writes that the disease is more common in people whose teeth have been neglected and in people whose immune system is suppressed.

An infection spreading from the upper teeth, on the other hand, can reach round the eye. MSD writes that infection of the tissues surrounding the eye socket (orbital cellulitis) can spread from the teeth and, in addition to swelling and redness of the eyelid, can push the eye forward, restrict and make painful the movements of the eye, and reduce vision. Among the complications of this condition, MSD lists loss of vision caused by rising pressure inside the eye socket, and cavernous sinus thrombosis, meningitis and brain abscess, which can develop as the infection moves inside the skull. Facial swelling in which the eyelid is starting to close is therefore a matter for A&E, not the dentist.

Measurements from dental infections treated in hospital show in whom the risk grows. Among 997 patients treated surgically over 12 years at Jena University Hospital in Germany, systemic complications affecting the bloodstream or other organs occurred in 3.8%; older age, chronic obstructive pulmonary disease (COPD), chronic alcohol dependence and the infection having spread to more than one space independently increased this risk. Involvement of more than one space also predicted a hospital stay of 10 days or more. The same study found that admissions for dental infection had risen over the years.

The picture on the airway side is similar. Of 349 patients in the US with a dental infection that needed drainage in the operating theatre, 10.3% needed a breathing tube (intubation) before or after the operation, and 3 patients had an airway opened through the throat. The two factors found to be associated with prolonged intubation were spread on CT to the space around the throat and a suppressed immune system. MSD gives the overall death rate in Ludwig's angina as about 3 in 1,000; the figure is based on emergency department visits in the US; the same source regards protecting the airway as the top priority of treatment.

The features in the first list fit a contained infection that can be treated at the dentist the same day. If even a single point from the second list applies, do not wait for a dental appointment; go to A&E.

With cellulitis and Ludwig's angina, the order deliberately starts with the airway. The source of the infection is only dealt with once the airway has been secured.

1. 1

   The airway first

   MSD writes that in Ludwig's angina the top priority is keeping the airway open. Because the swelling makes it hard to pass a tube through the mouth, in some patients the tube is placed through the nose while they are awake, using a flexible camera, and in others an airway has to be opened through the throat. Patients who do not need a tube straight away are monitored closely.

2. 2

   Mapping the spread: a CT scan

   The evidence-based review writes that if the patient can safely lie flat, a contrast-enhanced CT scan of the soft tissues of the neck is preferred, and that in patients who cannot lie flat a bedside ultrasound can help. The CT scan shows which spaces the infection has reached and whether there is a pocket to drain.

3. 3

   Broad-spectrum intravenous antibiotics

   MSD notes that antibiotics are chosen to work against both the bacteria in the mouth that live with oxygen and those that live without it. With cellulitis, waiting at home on antibiotics taken by mouth is no substitute for this treatment.

4. 4

   Surgical drainage and clearing the source

   MSD writes that in Ludwig's angina the pressure is relieved by incision and drainage, with drains placed deep in the muscle of the floor of the mouth. The tooth that is the source of the infection is also either removed or treated; as long as the source remains, the infection comes back.

5. 5

   Close monitoring

   The review recommends admitting these patients to intensive care so that the airway can be monitored closely. In the US series of 349 patients, those who needed a breathing tube for a long time stayed in hospital for 7.6 days on average, and those who did not for 3.6 days on average.

There is no single treatment for cellulitis; in hospital, several steps that complement one another are carried out together.

The following are decisions often made with a spreading facial infection that let the condition grow outside hospital.

The timings vary with how far the infection has spread and the procedures carried out. The sequence below is a general framework; the plan of the team treating you comes first.

1. The first day of admission

   The airway is secured, intravenous antibiotics are started and drainage is done if needed. During this period the swelling may well not go down straight away; the team monitors the airway and your general condition closely.

2. The hospital stay

   In the Australian series, patients admitted with a dental infection stayed 2.7 days on average; in the US series, patients who did not need a breathing tube for a long time stayed 3.6 days on average. With an infection that has spread to more than one space, the stay is longer.

3. The days after discharge

   The course of antibiotics the doctor has given is completed even if you feel well. Follow the instructions given for looking after the drains or the incision, and go to your follow-up appointment.

4. Definitive treatment of the source tooth

   If it was not removed in hospital, root canal treatment or extraction of the source tooth is completed by your own dentist. An untreated tooth is an open door for the same infection to start again.

We are not giving a single figure here; there is a huge difference in scope between a contained abscess drained at the dentist and Ludwig's angina monitored in intensive care. These are the items that determine it:

How far the infection has spread

An infection that stays in one space and one that has spread to several spaces mean different procedures and different lengths of hospital stay.

Airway intervention

Close monitoring, a tube or an airway opened through the throat, and intensive care change the scope considerably.

Surgical drainage

Drainage in the operating theatre, looking after the drains and the need for repeat drainage are separate items.

Treating the source tooth

Extraction or root canal treatment is a separate step, done in hospital or by your own dentist after discharge.