Lemierre’s syndrome: an uncommon sequel of deep neck space infection

A 32-year-old male presented with swelling in the left submandibular and submental regions for 3 days, which was insidious in onset and progressive in nature. Two days after the onset of swelling, he developed fever, odynophagia and a change of voice; however, there was no dyspnoea. Local inspection of the neck revealed a diffuse swelling over the left submandibular and submental regions extending across the midline, without overlying skin changes. Palpation revealed a firm-to-soft, tender swelling with local warmth. Oral and oropharyngeal examination showed no dental foci or other sources of infection except for a swelling of the left lateral pharyngeal wall and erythema of the posterior pharyngeal wall. Rigid endoscopy performed with a 70-degree scope was normal. Laboratory investigations revealed leukocytosis with a total leukocyte count of 19,000 cells/mm³. Ultrasonography of the neck revealed an organised collection in the left parapharyngeal region, from which approximately 2mL of purulent material was aspirated and sent for culture and sensitivity testing, which yielded no bacterial growth. Contrast-enhanced computed tomography (CECT) of the neck confirmed a 24×15mm peripherally enhancing hypodense collection in the left parapharyngeal space, along with thrombosis of the ipsilateral internal jugular vein (Figures 1 and 2). The patient was started on intravenous amoxicillin–potassium clavulanate 1.2g every 8 hours and metronidazole 500mg every 8 hours, and intravenous unfractionated heparin (5000IU four times daily) with a target activated partial thromboplastin time (APTT) of 1.5–2 times the baseline.

During hospitalisation, the patient showed gradual improvements in pain, swelling and fever. Follow-up ultrasonography demonstrated a resolving collection in the left parapharyngeal region. The patient was discharged on oral amoxicillin–clavulanic acid 625mg thrice daily for 2 weeks, along with an oral anticoagulant rivaroxaban 2.5mg twice daily for 3 months. He was asymptomatic at 2 months follow-up.

Discussion

Patients with deep neck space infections (DNSIs) present with fever, neck pain, odynophagia, dysphagia, trismus or neck swelling, depending on the involved compartment.¹ CECT is the gold-standard investigation for assessing the extent of infection, identifying abscess formation and detecting vascular complications such as internal jugular vein thrombosis (IJVT). Laboratory investigations typically demonstrate leukocytosis and raised inflammatory markers, supporting an infective aetiology. The most frequently implicated organisms in DNSI with IJVT include Fusobacterium necrophorum, Streptococcus species, Staphylococcus aureus, Bacteroides spp. and mixed anaerobic oral flora.^2,3 Management requires prompt initiation of broad-spectrum intravenous antibiotics covering both aerobic and anaerobic organisms. Surgical drainage is indicated in cases with large or loculated abscesses, airway compromise or mediastinal spread.^1,2

The role of anticoagulation in IJVT remains controversial. Although high-quality evidence is limited, anticoagulants are considered beneficial in preventing thrombus propagation, facilitating recanalisation and reducing the risk of embolic complications.⁴ The most feared complication of IJVT associated with deep neck infection is septic pulmonary embolism, which can lead to respiratory distress, sepsis and multi-organ failure if not promptly recognised and treated.³

Conclusion

This case highlights the need for heightened clinical vigilance in patients with progressive DNSIs, particularly those with persistent fever and increasing neck swelling, as even localised infections may rapidly progress to Lemierre’s syndrome. Hence, prompt contrast-enhanced imaging should be done to exclude IJVT and enable timely multidisciplinary management.

View Figure 1–2.