What Is Lemierres Syndrome? Symptoms And Treatment

Lemierre’s syndrome is a rare but serious infection that starts in the throat and spreads to the jugular vein in the neck. It causes a blood clot in that vein and then bacteria travel through the bloodstream to other parts of the body, most often the lungs. This condition requires immediate medical attention and intravenous antibiotics to treat the infection and prevent life-threatening complications.

What Causes Lemierre’s Syndrome?

Lemierre’s syndrome almost always begins with a bacterial infection in the throat. The most common cause is a type of bacteria called Fusobacterium necrophorum. This bacterium is normally found in the mouth and throat without causing problems. But sometimes it invades deeper tissues.

The infection usually starts as pharyngitis or tonsillitis. From there it spreads to the peritonsillar space and then into the internal jugular vein. Once the vein is infected a blood clot forms. The bacteria then break off from the clot and travel through the bloodstream. This spreading of bacteria is called septicemia or blood poisoning.

Research published in the journal Clinical Infectious Diseases has found that Fusobacterium necrophorum is responsible for roughly 80 percent of Lemierre’s syndrome cases. Other bacteria like Streptococcus species can also cause it but much less often.

Young adults and teenagers are most at risk. The CDC notes that the typical patient is a previously healthy adolescent or young adult between 15 and 25 years old. However cases have been reported in older adults and in children as young as two years old.

What Are the Early Symptoms of Lemierre’s Syndrome?

The early symptoms look exactly like a bad sore throat or tonsillitis. This is why the condition is often missed in the first week. Patients typically have a severe sore throat fever chills and difficulty swallowing. The throat may look red and swollen with white patches on the tonsils.

After about four to five days a key change happens. The sore throat may start to improve but the fever gets worse. The patient develops severe neck pain and swelling on one side of the neck. This swelling is from the infected jugular vein and surrounding tissue. It is often tender to the touch.

Other early symptoms include fatigue headache and general weakness. Many patients report feeling worse than they ever have from a normal sore throat. The fever is usually high often above 102 degrees Fahrenheit.

A study in The Lancet Infectious Diseases found that neck pain and swelling appear in about 70 percent of confirmed cases. But in the remaining 30 percent the neck symptoms are mild or absent. This makes the diagnosis easy to miss.

What Are the Later Symptoms and Complications?

Once the bacteria spread beyond the neck the symptoms change. The most common site for secondary infection is the lungs. Patients develop shortness of breath chest pain and a cough. They may cough up blood. Chest X-rays often show multiple small abscesses or pockets of infection in the lungs.

The joints are the second most common site. About 20 to 30 percent of patients develop septic arthritis. This means bacteria have invaded one or more joints causing intense pain swelling and redness. The knees hips and shoulders are most often affected.

Other organs can be infected too. The liver spleen kidneys and brain are all possible targets. When the infection reaches the brain it can cause meningitis or brain abscesses. The heart can develop endocarditis which is an infection of the heart valves.

A blood clot in the jugular vein is the defining feature of Lemierre’s syndrome. But clots can also form in other veins. Some patients develop clots in the lungs called pulmonary emboli. These are separate from the lung infections and can be life-threatening on their own.

How Is Lemierre’s Syndrome Diagnosed?

Diagnosis starts with a high suspicion. Doctors must think of this condition when a young person has a severe sore throat followed by neck swelling and high fever. Blood tests show elevated white blood cell counts and markers of inflammation like C-reactive protein.

Blood cultures are essential. They can identify the specific bacteria causing the infection. However Fusobacterium necrophorum grows slowly in the lab. Cultures may take three to seven days to turn positive. Treatment often starts before the results come back.

Imaging is used to confirm the blood clot in the jugular vein. Ultrasound with Doppler is often the first test. It can show reduced or absent blood flow in the vein. A CT scan with intravenous contrast is more detailed. It can show the clot and also detect abscesses in the lungs or other organs. MRI is another option but is less commonly used in urgent situations.

A 2018 review in American Family Physician noted that the average time from first symptoms to diagnosis is about eight days. This delay is dangerous because the infection continues to spread during that time. Early diagnosis significantly improves outcomes.

What Is the Treatment for Lemierre’s Syndrome?

Treatment requires hospital admission. Intravenous antibiotics are the cornerstone of therapy. The antibiotics must cover anaerobic bacteria because Fusobacterium necrophorum is an anaerobe meaning it does not need oxygen to grow. Common choices include penicillin combined with metronidazole or a carbapenem antibiotic alone.

Antibiotic treatment typically lasts three to six weeks. Patients usually receive intravenous antibiotics for at least the first two weeks. After that they may switch to oral antibiotics to complete the course. The exact duration depends on how quickly the patient improves and how many organs are involved.

Drainage of abscesses is often needed. If the infection has formed pus collections in the lungs joints or other organs a surgeon or interventional radiologist must drain them. This is done with a needle guided by imaging. In severe cases open surgery may be necessary.

The role of blood thinners is debated. Some doctors prescribe anticoagulants to dissolve the clot in the jugular vein. Others do not because the clot often resolves on its own once the infection is treated. Research published in Thrombosis Research suggests that anticoagulation may help when the clot extends into the large veins of the chest. But there is no strong consensus. Your doctor will make this decision based on your specific situation.

Supportive care is also important. Patients may need oxygen if their lungs are affected. Pain management and fluids are given as needed. Physical therapy may be required later if joints were damaged.

What Is the Outlook for Someone With Lemierre’s Syndrome?

With prompt treatment the outlook is good. Mortality rates have dropped dramatically since antibiotics became available. In the early 1900s before antibiotics about 90 percent of patients died. Today the death rate is between 4 and 8 percent according to data from multiple case series.

Full recovery takes time. Most patients spend two to three weeks in the hospital. After discharge many continue oral antibiotics for another two to four weeks. Fatigue and weakness can persist for months. Some patients have lasting joint damage or lung scarring but this is less common with early treatment.

Relapse is rare but possible. Patients should follow up with their doctor to make sure the infection is completely gone. Repeat imaging may be done to confirm that abscesses and clots have resolved.

Some people report that Lemierre’s syndrome is making a comeback. The number of reported cases has increased since the 1990s. Some researchers believe this is because doctors are more aware of it and diagnose it more often. Others think it is a real increase possibly related to less use of antibiotics for sore throats. The CDC estimates the incidence at about one case per million people per year in the United States. It is still very rare.

Common Misconceptions About Lemierre’s Syndrome

One common myth is that Lemierre’s syndrome is contagious. It is not. The underlying bacteria can spread from person to person through respiratory droplets but the syndrome itself is not contagious. Most people who carry Fusobacterium necrophorum in their throats never develop the condition.

Another misconception is that it only affects people with weak immune systems. Actually most cases occur in previously healthy young people with normal immune function. No one knows exactly why some people develop this severe complication from a simple sore throat while most do not.

Some people believe that having your tonsils removed prevents Lemierre’s syndrome. There is no evidence for this. While tonsillectomy may reduce the risk of severe tonsillitis it does not eliminate the risk of this condition. Cases have been reported in people who had their tonsils removed years earlier.