Lemierre's Syndrome

What Is Lemierre’s Syndrome? Symptoms, Causes, Diagnosis, Treatment, and More

Katherine Lee
By Medically Reviewed by 
Reviewed:
Medically Reviewed

Lemierre’s syndrome is a rare disease that occurs when a bacterial infection (usually a throat infection) spreads into the tissues and deep spaces within the neck and forms a blood clot in the jugular vein.

The infected clot then travels in the blood to other parts of the body, typically the lungs, which can cause life-threatening complications.

In the era before the availability of antibiotics, the mortality rate for Lemierre’s was extremely high. But widespread use of antibiotics led to no cases being reported in the 1950s or 1960s, prompting Lemierre’s to be dubbed “the forgotten disease.”

That began to change in more recent decades, with studies showing about 0.8 to 1.5 million cases a year being reported worldwide between the years 1970 to 2007. Some theories for the reasons behind this uptick include increases in antibiotic resistance and changes in prescription patterns due to the awareness of this growing problem.

Today, Lemierre’s syndrome may not be as rare as once thought, and it’s considered a reemerging infection. Lemierre’s is more commonly seen in young adults, and doctors should consider the possibility of this disease in certain cases of persistent neck pain, deep neck infections, septicemia (a serious bloodstream infection), and other signs of Lemierre’s syndrome.

Signs and Symptoms of Lemierre’s Syndrome

Lemierre’s syndrome most commonly starts with a throat infection. It can also start with an infection in the ear, sinuses, salivary glands, or teeth, or due to an Epstein-Barr infection.

Typical symptoms of Lemierre’s syndrome include:

  • Persistent fever
  • Chills
  • Pain, tenderness, and swelling in the throat and neck
Swelling and tenderness in the neck are key early signs that the infection has moved out of the throat and into the surrounding tissue.

Age can be a factor in which symptoms appear first: Most young people initially experience a sore throat, whereas older individuals tend to first be diagnosed with complications of the infection, such as empyema (a lung condition in which pus collects in the space between the lung and the inner surface of the chest wall) or brain abscess.

Causes and Risk Factors of Lemierre’s Syndrome

Lemierre’s syndrome is typically caused by Fusobacterium necrophorum, a bacteria that lives in the throat, digestive tract, and female genitals.

F. necrophorum may cause Lemierre’s syndrome by releasing toxins into the surrounding tissue. It’s also been suggested that in some cases, a different bacteria or virus may be responsible for an initial infection, which can then set the stage for Lemierre’s to develop. These possible initial viruses and infections include Epstein-Barr virus and streptococcal infection.

Risk Factors

Risk factors for Lemierre’s syndrome include:

  • Being immunocompromised
  • Environmental conditions

How Is Lemierre’s Syndrome Diagnosed?

To diagnose Lemierre’s, doctors typically evaluate signs and symptoms as well as blood tests and imaging studies.

Blood tests may show signs of infection or clotting problems as well as indications of abnormal liver or kidney function. Imaging tests may include a chest X-ray, ultrasound, MRI, or a CT scan of the neck. Magnetic resonance venography (MRV) may be used to detect clots in the jugular vein.

Lemierre’s syndrome should be considered in young, otherwise healthy individuals with a worsening throat infection and other key symptoms of the condition.

Prognosis of Lemierre’s Syndrome

While Lemierre’s syndrome is more treatable today, it can still be a life-threatening condition. The mortality rate for Lemierre’s infections that are in advanced and serious stages is approximately between 5 and 18 percent.

Hospitalizations for advanced Lemierre’s typically involve stays in intensive care units, and the disease can cause permanent long-term damage.
The good news is that getting the right diagnosis and treatment as early as possible can make a difference and increase your chance of survival.

Duration of Lemierre’s Syndrome

How long you are affected by Lemierre’s syndrome depends greatly on when you get a diagnosis and begin treatment and how far your disease has progressed. Typically, doctors will treat patients with antibiotics for up to six weeks.

For severe disease that has progressed, hospital admission to an intensive care unit may be necessary. The average length of hospitalization for Lemierre’s is approximately three weeks.

Treatment and Medication Options for Lemierre’s Syndrome

Given the wide-ranging complications that can occur in severe or untreated Lemierre’s, it's ideal to have a healthcare team of specialists including an infectious disease specialist, an otolaryngologist, pharmacologists, radiologists, and a thoracic surgeon working together to treat someone who has this infection.

The two main components of treatment for Lemierre’s syndrome are antibiotics and drainage at the sites of infection.

In cases where antibiotic therapy and drainage are not working, doctors may turn to surgery to remove infected blood clots. Surgery may also be used to treat blood clots that are causing breathing problems or are occurring in the brain or to remove dead or damaged infected tissue from the body.

Medication Options

Antibiotics are usually delivered intravenously at first and may be switched to oral antibiotics once the infection is under control.

Typically, doctors prescribe a combination of different antibiotics for up to six weeks to allow the medication to penetrate infected clots.

Metronidazole (Flagyl) in particular is commonly used to treat Lemierre’s syndrome and appears to be among the most effective antibiotic treatments for the illness, along with carbapenems and beta-lactam/beta-lactamase inhibitor combinations.


Another treatment strategy doctors may consider is using blood thinners for blood clots. This method is controversial and questions have been raised about its risks and effectiveness. While anticoagulation therapy may help prevent new clots from forming, it may also elevate the risk of bleeding complications and other problems.

Complications of Lemierre’s Syndrome

When an infected blood clot caused by Lemierre's syndrome travels in the bloodstream, it can spread infection to the lungs, skeletal system, and other organs such as the spleen, liver, kidney, heart, or brain.

Other complications may include:

  • Pneumonia, lung lesions, abscesses, and pleural effusions (fluid around the lung)
  • Empyema
  • Epidural abscess (an abscess between your skull and your brain)
  • Brain abscess
Serious complications may include:

  • Respiratory distress syndrome due to pulmonary emboli (blood clots in the lung)
  • Damage to other affected organs
  • Septic shock (in about 7 percent of cases)
  • Bone infection
  • Meningitis
Less common complications may include:

  • Soft tissue abscesses
  • Pyomyositis (bacterial infection of the skeletal muscle)
  • Abscesses in the spleen and liver
  • Endocarditis (inflammation of the heart’s inner lining and valves)
  • Pericarditis (inflammation of the membrane surrounding the heart)
  • Renal abscess (kidney abscess)
  • In rare cases, eye complications

Research and Statistics: Who Has Lemierre’s Syndrome?

Lemierre’s typically affects young and healthy people. The median age of people with the infection is between 19 and 22 years of age. And approximately 90 percent of people who develop Lemierre’s are between 10 and 35 years old.

Men are more likely to be diagnosed with Lemierre’s syndrome: The male-to-female ratio is 2 to 1.

Related Conditions and Causes of Lemierre’s Syndrome

In addition to F. necrophorum, other viruses and infections linked to Lemierre’s syndrome include Epstein-Barr virus and streptococcal infection (strep).

Lemierre’s syndrome is also frequently mistaken for mononucleosis.

Resources We Love

Genetic and Rare Disease Information Center (GARD)

Funded by the National Institutes of Health, this site lays out the key facts about Lemierre’s syndrome and other rare diseases, from causes to diagnosis to treatments.

StatPearls

This source from the National Center for Biotechnology Information (NCBI) offers information about how Lemierre’s syndrome can affect the body and why early diagnosis is important.

Editorial Sources and Fact-Checking

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