Lemierre's syndrome

Overview

Lemierre’s syndrome is a rare but potentially life-threatening bacterial infection that begins in the throat and leads to septic thrombophlebitis of the internal jugular vein, often accompanied by the spread of infection to the lungs and other organs. It typically follows an episode of pharyngitis or tonsillitis and progresses rapidly if not treated. Once referred to as the "forgotten disease" due to its rarity in the antibiotic era, Lemierre’s syndrome has seen a resurgence in recent years, especially among young adults.

Causes

The primary cause of Lemierre’s syndrome is infection with the anaerobic bacterium Fusobacterium necrophorum, which is part of the normal flora of the oropharynx. The syndrome develops when this bacterium invades the surrounding tissues following a primary throat infection. The infection can spread to the parapharyngeal space and cause:

• Septic thrombophlebitis (infected blood clot) of the internal jugular vein

• Septic emboli – bacteria-laden clots that travel to the lungs or other organs

Other bacteria, such as Streptococcus species or Staphylococcus aureus, may also contribute, but Fusobacterium necrophorum is most commonly implicated.

Symptoms

Symptoms of Lemierre’s syndrome typically begin with a sore throat and fever but progress quickly to systemic illness. Common signs and symptoms include:

• Severe sore throat – often with tonsillar or peritonsillar infection

• High fever and chills

• Neck pain and swelling – particularly over the sternocleidomastoid muscle, due to internal jugular vein involvement

• Difficulty swallowing (dysphagia)

• Shortness of breath, chest pain, or cough – due to septic emboli in the lungs

• Fatigue, malaise, and sepsis – signs of systemic infection

Diagnosis

Diagnosing Lemierre’s syndrome requires a high index of suspicion, especially in patients with recent oropharyngeal infection and signs of systemic illness. Diagnostic tools include:

• Blood cultures – to identify Fusobacterium necrophorum or other pathogens

• Ultrasound or CT scan of the neck – to detect thrombosis in the internal jugular vein

• Chest X-ray or CT scan – to identify septic emboli in the lungs

• Complete blood count (CBC) – often reveals elevated white blood cell count

Early imaging is essential to confirm venous thrombosis and assess the extent of infection.

Treatment

Prompt initiation of antibiotic therapy is critical in managing Lemierre’s syndrome. Treatment typically includes:

• Intravenous antibiotics – such as beta-lactam/beta-lactamase inhibitors (e.g., piperacillin-tazobactam), carbapenems, or a combination including metronidazole to cover anaerobes

• Anticoagulation therapy – may be considered in some cases to prevent thrombus propagation, though its use remains controversial

• Surgical drainage – of abscesses or infected thrombosed veins if indicated

• Supportive care – including fluids, oxygen, and management of sepsis

Hospitalization is usually required, often in an intensive care setting, especially if respiratory or multiorgan involvement is present.

Prognosis

With early diagnosis and aggressive antibiotic treatment, the prognosis for Lemierre’s syndrome has significantly improved. Most patients recover fully, although the illness can be severe and prolonged. Complications may include lung abscesses, septic arthritis, and persistent thrombosis. Without treatment, the condition can be fatal. Therefore, awareness and prompt intervention are essential for favorable outcomes.