What is Lemierre Syndrome?
Lemierre syndrome (LS) is a disease named after a French doctor, Andre Lemierre. He reported 20 cases of a rare type of blood infection, known as anaerobic septicemia, in 1936 that started from throat infections. LS is a rare but serious condition that can occur after a bacterial throat or tonsil infection. The disease can then spread to the sides of the neck, leading to a severe condition where clots form in the internal jugular veins (veins in the neck) and cause a potentially fatal blood infection. This severe condition can affect even healthy young individuals. Diagnosing LS can be challenging as throat infections are common in the young population, and its symptoms can be mistaken for less severe conditions. This can often lead to delays in getting the right treatment.
What Causes Lemierre Syndrome?
Lemierre syndrome begins as a result of a severe throat infection caused by bacteria. The most common bacteria linked to this condition are Fusobacterium necrophorum and Fusobacterium nucleatum. These bacteria can cause severe infections due to harmful substances they produce, known as endotoxins and exotoxins. Other bacteria, including Streptococcus species, Bacteroides species, Staphylococcus aureus, and Klebsiella pneumoniae, have also been reported to cause Lemierre syndrome based on case studies.
Fusobacterium necrophorum is usually a harmless part of the bacteria present in the throat, digestive tract, and the female reproductive system. However, other types of throat infections can create an environment that promotes its growth. These can be caused by viruses (like acute Epstein Barr) or bacteria (like strep throat). Conditions like a peritonsillar abscess, a pus-filled swelling around the tonsils, can also provide an environment where these bacteria can thrive and invade surrounding tissues.
The infection can then spread from the throat into a space beside the throat, which can lead to a condition where bacteria enter the internal jugular vein (a large blood vessel in the neck). This can cause a blood clot to form in the vein, leading to a whole body infection and clumps of bacteria being carried in the bloodstream to other parts of the body. This situation is known as septicemia and septic emboli.
Risk Factors and Frequency for Lemierre Syndrome
Lemierre syndrome was a lot more common before the use of antibiotics became widespread. With the start of penicillin use in the 1960s and 1970s, fewer cases were reported. Since the late 1970s though, cases have been slowly increasing again, possibly due to less use of precautionary antibiotics for throat infections. Even so, it’s still a pretty rare syndrome, affecting only about 1 in 1,000,000 people worldwide. Most of the people it affects are healthy young people, from adolescents to young adults. The average age of someone with Lemierre syndrome is between 19 to 22 years old.
- Most of the patients affected by Lemierre syndrome are between the ages of 10 and 35, accounting for 90% of all cases.
- In studies, it is reported to affect males twice as much as females.
Signs and Symptoms of Lemierre Syndrome
Lemierre disease, also known as Lemierre syndrome, is a medical condition that develops in stages and usually follows a pattern. Understanding these stages can assist doctors in diagnosing the syndrome accurately.
Oropharyngeal Infection
The initial symptoms of Lemierre syndrome are linked to an infection in the throat (oropharyngeal infection). Typically, these symptoms include fever and chills appearing 4 to 7 days after the beginning of the infection. It can be challenging to diagnose early as these symptoms are similar to other common throat infections. Many people will have had a throat infection before the onset of Lemierre syndrome. However, it can also develop from other infections such as those of the ear, sinuses, mastoid bone (behind the ear), salivary glands, or teeth. It is important to note that the syndrome might be delayed in being diagnosed in individuals who tested positive for Epstein-Barr virus infection, a common cause of mononucleosis. The fact that symptoms persist and worsen after a week can be a vital clue.
Infection Extension to the Parapharyngeal Space of the Neck with Thrombophlebitis of the Internal Jugular Vein
If your throat infection is spreading with neck pain and swelling, it might indicate that the infection is progressing beyond the throat. A particular sign known as the “cord sign,” that is, a hard and tender swelling at the jaw’s angle, suggests the formation of a clot in the internal jugular vein, talking place in 25% to 45% of cases. A carefully conducted examination of the neck can reveal signs of skin infection (cellulitis), indicative of the infection spreading to the neck veins and the structures in the central part of the chest (mediastinal structures).
Septic Emboli
Once the bacterium F. necrophorum invades the neck veins, septic clots (emboli) start to occur. These clots mostly affect the lungs (in 85% of cases), but they also can reach other organs such as joints, liver, kidney, brain, bones, heart, or the meninges (membranes covering the brain and spinal cord). Bloodstream infection (bacteremia) that comes with fever, listlessness, or shock can result in damage to these organs. Nearly 7% of the cases may progress into septic shock. Furthermore, acute respiratory distress syndrome requiring assisted ventilation could happen in up to 10% of patients.
Testing for Lemierre Syndrome
If you are suspected to have Lemierre syndrome, your doctor will start by observing your symptoms, but additional tests can also help. These might include a variety of lab tests that are often used for patients suspected of having a severe infection or an abnormal response to a harmful event.
Abnormalities that your doctor might look for include a high white blood cell count, kidney complications, abnormal liver tests such as increased bilirubin, low platelet count, and other signs of widespread, uncontrolled blood clotting.
Blood cultures, or samples, can also be taken to check for specific bacteria; the growth of bacteria typically takes about 2 to 7 days to appear. The results often show a type of bacteria called Fusobacterium in more than 70% of cases. However, in some instances, the blood culture may not show any growth due to challenges in culturing bacteria that thrive in environments with negligible oxygen.
When it comes to imaging, your doctor may order a chest x-ray. That’s because the lungs are the most common place for the infection to spread. The x-ray will look for infections or clots in your lungs and other lung complications, including fluid build-up, lung abscesses (pus-filled spaces), and empyemas (pus in the pleural space).
The infection can also spread to other areas, causing septic arthritis (joint infection), osteomyelitis (bone infection), meningitis (brain and spinal cord membrane infection), pericarditis (heart lining infection), and liver abscesses (pus-filled spaces in the liver).
Other imaging techniques can include ultrasound, CT scans, and MRI, especially for viewing the jugular vein in your neck for any potential clotting. MRI has the highest sensitivity (ability to correctly identify positive cases) for accurately detecting this type of clot, while CT is more commonly used in clinical practice because of its widespread availability. Ultrasound is cheaper and doesn’t involve exposing you to radiation, but it may not be as effective in detecting fresh clots or clots in the lower part of the neck due to its lower sensitivity.
Treatment Options for Lemierre Syndrome
Lemierre syndrome is usually treated with antibiotics. The specific antibiotic we use may vary depending on your condition, but a type of antibiotic that isn’t affected by certain defense mechanisms of the bacteria causing the condition (F. necrophorum) is a typical first choice. We might have to make adjustments to your antibiotics based on what we learn from tests on your infection. If beta-lactams, an antibiotic commonly used, causes an allergic reaction, we may switch to two other types of antibiotics such as clindamycin or metronidazole. For most patients, the antibiotic treatment lasts for six weeks to make sure we totally get rid of the infection, even if it’s hiding in clots in your blood.
Sometimes we need to move to surgery if the condition has caused serious complications such as build-up of pus, difficulty breathing due to blood clots in lungs, and infection spreading to other parts in the body or a thrombus (a blood clot) spreading to the chest or brain. In these cases, a surgical intervention may be necessary to cut open and drain the pus to manage the infection.
Certain scenarios require the use of anticoagulants, or blood thinners. They’re not typically used for uncomplicated cases of Lemierre syndrome. If the infection is controlled well with antibiotics and supportive care and without significant blood clot burden, you likely won’t need them. But in some cases, like a spreading blood clot to cerebral sinuses (channels that drain blood from the brain), the presence of large or double-sided clots, or if conditions don’t improve within 72 hours despite therapy, anticoagulants are generally recommended. However, it’s essential to remember that the use of blood thinners in Lemierre syndrome is open to discussion and varies depending upon the expert’s view and the patient’s condition.
What else can Lemierre Syndrome be?
Early symptoms of Lemierre’s syndrome (LS) can be confusing because they appear like other common throat infections caused by both viruses and bacteria. As Lemierre’s syndrome progresses, it can appear to be any condition that causes bacteria to spread throughout the body, sometimes landing in and affecting other organs.
So, when diagnosing early-stage Lemierre’s syndrome, doctors have to consider all possible causes of throat infections, including:
- Viral infections
- Bacterial infections
And for advanced Lemierre’s syndrome, it can resemble any condition that leads to widespread bacteria in the body, with or without bacteria landing in and affecting other organs.
What to expect with Lemierre Syndrome
Lemierre syndrome is a very serious condition. Despite receiving the right antibiotics and treatment, the death rate has been reported to range from 5% to 18%. Often, patients are admitted to the intensive care unit (ICU) at the hospital, typically for about three weeks.
Challenges can further develop if bacteria from the infection spread to other parts of the body causing illness (referred to as septic emboli), or affect the functioning of crucial body organs like the heart or liver, leading to long-term health issues.
