Abstract A 17-year-old male patient presented to our emergency depart- ment for fever, persistent sore throat and right-sided neck pain despite antibiotics, and dehydration. He was found to have throm- bosis of the right facial vein and diffuse septic emboli. Blood cul- ture tested positive for Fusobacterium necrophorum, leading to a diagnosis of Lemierre Syndrome (LS). LS is a life-threatening con- dition characterized by thrombosis of the internal jugular vein, anaerobic bacteraemia, and diffuse septic emboli. It should be sus- pected in healthy young patients who present with persistent sore throat or atypical lateral cervical pain, followed by sepsis and bronchopneumonia. Diagnosis is confirmed through the identifica- tion of jugular venous thrombosis and is supported by the growth of anaerobic bacteria in blood cultures. Treatment is based on pro- longed targeted antibiotic therapy and hydration. The indication for anticoagulant therapy remains a topic of debate. Our patient was treated with antibiotics and anticoagulant therapy, resulting in a good clinical response and subsequent complete recovery. Introduction Lemierre Syndrome (LS) was first described in 1900 by Courmount and Cade, who reported a case of suppurative internal jugular vein thrombophlebitis associated with oropharyngeal infection.1 In 1936, the French microbiologist André Lemierre described a series of 20 cases of “post-anginal septicaemia”.2,3 The syndrome is characterised by a recent oropharyngeal infection, thrombosis of the internal jugular vein, and severe anaerobic sep- ticaemia generally caused by Fusobacterium necrophorum. Starting with the description of a case of LS in a young male patient, we conducted a review of recent data regarding the epi- demiology, etiopathogenesis, clinical presentation, diagnostic cri- teria, and treatment of this syndrome. Our research involved a comprehensive review of the relevant literature available on PubMed and Google Scholar from 2015 to the present. Case Report A 17-year-old male patient, who had been in excellent health Emergency Care Journal 2025; volume 21:13720 [Emergency Care Journal 2025; 21:13720] [page 49] From a sore throat to Lemierre syndrome. A case report and literature review Andrea Drei, Gianluigi Rava, Silvia Predieri, Lucio Mari, Gabriele Farina Emergency Department, Ospedale degli Infermi, Faenza, Italy Correspondence: Andrea Drei, Emergency Department, Ospedale degli Infermi, viale Stradone 9, Faenza, Italy. Tel: +39.0546601284 E-mail: andreadrei2006@gmail.com Key words: Lemierre syndrome; sepsis; Fusobacterium necropho- rum; pharyngitis; jugular vein thrombosis. Contributions: AD drafted the manuscript. GR, AD, SP, LM, GF cared for the patient. GF critically revised the manuscript. All authors approved the final version and stated the integrity of the whole work. Conflicts of interest: the authors declare no conflict of interest. This work was not supported by any grant. Availability of data and materials: all data underlying the findings are fully available upon reasonable request to Andrea Drei, andread- rei2006@gmail.com. Ethics approval and consent to participate: as this was a descriptive case report and data was collected without patient identifiers, ethics approval was not required under our hospital’s Institutional Review Board guidelines. The patient gave his written consent to use his data for the publication of this case report and any accompanying images. Acknowledgements: the authors thank the Radiology Department of the Hospital of Faenza, particularly Dr Filomena La Sala and Dr Rossana Santostefano. Received: 10 February 2025. Accepted: 15 March 2025. Early view: 2 April 2025. This work is licensed under a Creative Commons Attribution 4.0 License (by-nc 4.0). ©Copyright: the Author(s), 2025 Licensee PAGEPress, Italy Emergency Care Journal 2025; 21:13720 doi:10.4081/ecj.2025.13720 Publisher's note: all claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher. Highlights - Lemierre Syndrome (LS) is a rare but potentially life- threatening septic condition; - LS usually begins with pharyngotonsillitis primarily affecting young adults; - LS manifests as thrombophlebitis of the internal jugular vein, diffuse septic emboli, and anaerobic septicaemia; - Fusobacterium necrophorum is often identified as a causal agent; - Early recognition and prolonged antibiotic therapy are essential to prevent mortality and severe permanent complications. until a few days prior, presented to our emergency department for high fever, asthenia, headache, and pharyngodynia persisting for the past two days and not responsive to azithromycin 500 mg daily and oral ketoprofen 80 mg q12h. He also reported right-sided neck pain and odynophagia. His medical history included retinoblas- toma with the enucleation of the right eye in early childhood and a few episodes of pharyngotonsillitis. He denied any allergies. At admission, his vital parameters were as follows: blood pressure 90/60 mm Hg, heart rate was 123 bpm, and body temperature 35.8°C. Physical examination revealed pharyngeal hyperaemia with slight whitish exudate, as well as swelling of the submandibu- lar lymph nodes. Cardiac, pulmonary, and abdominal evaluation was normal. Laboratory tests documented increased inflammation indexes with C-reactive protein 331 mg/dL (normal value <5) and procalcitonin 99.20 mcg/L (normal value <0.5) with leucocytosis (WBC 16,800/mm3 - neutrophils 93%), and renal damage with cre- atinine 2.05 mg/dL (normal value 0.70-1.20) and normal serum electrolytes (Table 1). Epstein Barr serology, Legionella and pneu- mococcal urinary antigen resulted negative. Chest X-ray, electro- cardiogram, and abdominal ultrasound bedside were normal. The patient was hospitalized in the emergency medicine ward. Antibiotic therapy with amoxicillin clavulanic acid intravenously (1000/200 mg q8h), analgesic therapy with intravenous ketopro- fene 100 mg q12h, and hydration with crystalloids (1500 mL daily) were started. Over the following days, his clinical condition remained stable, but he developed nausea, vomiting, and a slight thrombocytopenia with increased total bilirubin (Table 1). On day 5, he underwent pharyngeal fibroscopy that showed acute tonsilli- tis with hemorrhagic area on the right tonsil, without fibrinous plaques, nor signs of phlegmon or abscesses and extreme pain when palpating the neck. A total-body CT scan with contrast medi- Article Table 1. The patient’s laboratory findings at admission and during recovery. CRP, C-reactive protein. PCT, procalcitonin. Normal values are in brackets. Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 On discharge Leukocytes (4,5-13x103/mm3) 16,810 14,870 6,490 10,150 11,560 11,430 7,620 Neutrophil (1,5-6x103/mm3) 15,640 13,810 4,160 7,050 8,260 7,300 4,290 CRP (<5.0 mg/L) 331 324 138 94 93 69,6 5,5 Creatinine (0.70-1.20 mg/dL) 2,05 2,02 1,04 1,04 1,12 Platelets (140–400×103/mm3) 147,000 113,000 92,000 131,000 237, 000 615,000 PCT (<0.5 ng/mL) 99,20 4,66 0,22 Total bilirubin (1.20 mg/dL) 3,16 1,46 Indirect bilirubin (mg/dL) 1,47 0,66 Figure 1. CT of the neck with contrast medium: a filling defect of the right facial vein is highlighted. Figure 2. Chest CT showing multiple nodular parenchymal thick- right lung, expression of septic emboli. [page 50] [Emergency Care Journal 2025; 21:13720] um was performed revealing thrombosis of the common facial vein and its tributary branches (Figure 1), diffuse pulmonary parenchy- mal inflammatory nodules (maximum diameter of 2 cm; Figure 2), and bilateral renal involvement compatible with pyelonephritis (Figure 3). On day 5, the blood culture performed at admission resulted positivity for Fusobacterium necrophorum. A diagnosis of LS was finally made and the antibiotic therapy was switched to piperacillin-tazobactam (4.5 gr q6h IV) and clindamycin (600 mg q8h IV). Full-dose enoxaparin therapy was initiated subcutaneous- ly (8000 I.U. q12h). A brain CT scan with contrast medium and an echocardiogram were performed and resulted negative. On day 6, antibiogram showed susceptibility for piperacillin-tazobactam, meropenem, clindamycin and metronidazole. According with the infectiologist, clindamycin was replaced with metronidazole (500 mg q8h iv). We observed a gradual clinical improvement with deferves- cence, a progressive reduction in pharyngeal and lateral cervical pain, normalization of renal function, and a decrease in inflamma- tory markers to normal levels (Table 1). On day 16, the patient was discharged in full wellbeing. Two weeks later, he underwent a total-body CT scan that confirmed the complete resolution of inflammatory foci and vein recanalization. Discussion According to the original description, LS is characterised by pharyngotonsillitis complicating with jugular vein thrombosis and severe anaerobic septicaemia. In a minority of cases, throm- bophlebitis may affect another vein in the head and neck.4 In our patient, the thrombosis affected the facial vein and its tributary branches. Epidemiology and aetiology LS mainly affects young adults. A recent systematic review found a median age of 21 years (inter-quartile range Q1-Q3 =17- 33)4 with a slight male prevalence (females 41%)4. Several cases are described in adolescence.2,5 It is a rare syndrome in the antibi- otic era, with an increasing incidence in recent decades, resulting in 5.5 cases per million of inhabitants in 2017.6,7 The reasons for this increase are not entirely clear. It has been hypothesized that this is due to the increase in antibiotic resistance or altered patterns in their prescriptions, as well as the decrease in tonsillectomies.8 Furthermore, greater diagnostic accuracy comes into play with the refinement of investigation techniques.2 Alcohol consumption and intravenous drug use has also been reported as favouring fac- tors.9,10 With regard to the aetiology, up to a third of cases manifests polymicrobial bacteremia.2 In a high percentage of cases Fusobacterium necrophorum is isolate. It is an anaerobic, gram- negative highly virulent bacillus, frequently isolated from the oropharingeal cavity. It appears to have vessel tropism and a ten- dency to activate directly the coagulation cascade and platelet aggregation.4 It has several factors that increase its virulence including adhesins, endotoxins, leukotoxins, and hemolysins, which increase its ability to cause a necrotic abscess.3,11 Other pathogens identified include Fusobacterium nucleatum, Bacteroides, Streptococci, Klebsiella pneumoniae,12 Eikenella cor- rodens,3 Escherichia Coli,13 Staphylococcus aureus with recent findings of methicillin-resistant strains.14 Some authors have hypothesized that an alteration of the pha- ryngeal mucosa, caused by a bacterial or viral infection, such as infectious mononucleosis,15 may promote the spread of the germ, which is normally non-invasive, with local dissemination in the lat- eral pharyngeal space, and with diffusion to the internal jugular through the tonsillar veins or the lymphatic system. In addition to the oropharyngeal origin, otomastoiditis especially in childhood, sinusi- tis, dental and gingival infections,16,17 bronchopneumonia and cel- lulitis are described as possible sources.2,7 Furthermore, some authors have postulated that the presence of a patent foramen ovale contributed to the arterial hematogenous spread of Fusobacterium necrophorum and extensive systemic embolization.18 Thrombophilic disorders may have a role in the presentation of LS.19 Mini review Table 2. The most typical and frequent signs and symptoms of Lemierre syndrome. Symptoms Signs Pharyngodynia Fever with chills Laterocervical pain Laterocervical swelling Myalgia Muscle stiffness Headache Dental infection Cough Purpura Odinophagy Jaundice Pleuritic chest pain Nausea/vomiting Figure 3. CT abdomen with contrast medium showing accumula- tion of contrast medium in the parenchyma of both kidneys com- patible with pyelonephritis. [Emergency Care Journal 2025; 21:13720] [page 51] Clinical presentation, course and prognosis The signs and symptoms of LS generally appear in two stages (Table 2).7 The first stage is a primary infection with oropharyngi- tis, fever with chills, and sore throat. The second stage is charac- terized by thrombophlebitis of the internal jugular vein or other vein in the head or neck, and sepsis, which may appear even sev- eral days after the first stage. It is important to know that signs of the previous infection can be resolved, and sepsis can mask the symptoms. Thrombophlebitis most frequently manifests with ipsi- lateral neck pain, headache, and laterocervical swelling.20 It is probably the result of endothelial dysfunction caused by the inflammatory factors of the local infection. Once septic thrombophlebitis of the internal jugular vein occurs, septic emboli can spread to different organs, mainly in the lungs with possible formation of abscesses and pleural empyema3. Spreads to the joints, liver and brain are also relatively frequent. Retrograde extension of septic thrombosis from the internal jugu- lar vein can cause brain or epidural abscesses.18 Osteomyelitis is reported in 3% of patient.2 Endocarditis and splenic emboli are very rare. In the clinical case described, there was bilateral renal spread, which has been described so far only exceptionally.2,4,7 The reported mortality rate is 3-4%,4 but it can be significantly increased if antibiotic treatment is delayed.7 Septic shock occurs in approximately 7% of cases. Acute respiratory distress syndrome due to necrotic cavitary lesions and requiring mechanical ventila- tion may affect up to 10% of patients.21 More than 10% of patients present permanent sequelae, mainly neurological, consisting of paresis of the cranial nerves,22 blind- ness, decreased visual acuity, and paresis of the limbs.7 In a recent systematic review, thromboembolic recurrences and septic emboli were described in 14% of cases more than one month after onset.4 Diagnosis The diagnosis of LS is essentially clinical, but its identification in the early stages can be a challenge, be virtually indistinguishable in its early stages from other conditions, particularly in young patients with recurrent benign oropharyngeal infections, leading to a delay in diagnosis and treatment with possible severe complica- tions, including a poor prognosis with fatal exitus.21 A Swedish ret- rospective study showed that 59% of patients were diagnosed and taken into care late.23 Moreover, its rarity may mean that emergen- cy physicians may not have encountered it in their practice.7,24 In some cases, the patient’s initial presentation can be confounded by an overlap SARS-CoV-2 infection.25 Traditionally, the key criteria for diagnosing LS are as fol- lows:2 i) sepsis originating from head or neck site, predominantly oropharyngeal; ii) thrombophlebitis of an internal jugular vein or other vein in the head or neck; iii) disseminated infection. Blood tests show significant increase of inflammation indexes and may show thrombocytopenia. Assay for EBV is positive in a very small percentage of cases.26 Blood cultures play a key role and the isolation of Fusobacterium necrophorum leads to the cor- rect diagnosis. It has been speculated that cases of failure to isolate Fusobacterium necrophorum may be due to false negatives as it is an anaerobic gram negative.6,7 For this reason, the use of PCR (Polymerase Chain Reaction) has been recommended in cases of negative blood cultures.9 With regard to diagnostic imaging, in 75% of the cases, some degree of pulmonary consolidation was shown on the X-ray, whereas 10% of the X-rays were reported as normal.27 Total body CT scan with contrast medium is generally considered the gold standard because of its ability to visualise both internal jugular vein thrombosis and organ damage. The doppler can be used to detect thrombosis but is less sensitive than CT, especially for newly formed or subclavian thrombi.1 MRI can be considered the most reliable technique although its use is limited by cost and availability. Compared to CT, it offers greater contrast in soft tis- sue, which makes it preferable in assessing neck abscesses, intracranial complications and metastases. However, it is less suit- able for the evaluation of intraparenchymal lung lesions.1 Therapy Antibiotic therapy is the mainstay of LS treatment. Metronidazole is particularly effective in the treatment of Fusobacterium necrophorum and is usually combined with car- bapenems or penicillins, especially piperacillin/tazobactam.2,3,7,19 The combination is strongly recommended, given the high fre- quency of mixed infections.23,7 Fusobacterium necrophorum is usually sensitive to penicillins, although recently beta-lactamase- producing strains have been isolated. It is also usually sensitive to cephalosporins, clindamycin, and chloramphenicol.19 It is naturally resistant to quinolones and aminoglycosides.28 It has dubious sen- sitivity to macrolides and tetracyclines.19,28 If CNS involvement is suspected, vancomycin, ceftriaxone, and metronidazole are recom- mended.3 The average duration of antibiotic treatment should be at least 3 weeks. Haemodynamic support may be required with fluid resuscitation and vasoactive agents (e.g., norepinephrine) ensuring end organ perfusion.3 Surgical treatment may sometimes be necessary for drainage of abscess collections, pleural empyema, and debridement of necrotic material.29 The indication for the use of anticoagulants appears controver- sial, and more than half of the patients receive anticoagulant ther- apy at different dosages.4 This may be due to the perceived unac- ceptable risk of increased bleeding and the fear that the anticoagu- lant may fragment the thrombus and cause new septic lesions. The studies performed showed no significant differences in the main outcomes, or in the occurrence of major bleeding, between patients treated and those not treated with anticoagulants.6,30 These studies are either retrospective or of limited size. It is the opinion of some authors that anticoagulant therapy should be adopted in the absence of contraindications as it can contribute to reducing the risk of relapses.4 It is likely that the bacteria within the thrombus may be less exposed to the action of the antibiotic and therefore a more rapid dissolution of the thrombus may help to treat the infec- tion advantageously.4,7,31 It may be plausible to consider 6 to 12 weeks as the ideal anticoagulation window.32 Two case reports lend support to the use of direct oral anticoagulants.32 Conclusions Emergency clinicians should consider LS in all the young patients who develop sepsis following a sore throat resistant to antibiotics. LS is a rare but life-threatening condition that can trig- ger a thrombotic and inflammatory response, potentially leading to multi-organ failure with a poor prognosis if not promptly identified and treated. Although the disease appears to be more common nowadays – possibly due to improved diagnostic sensitivity – its overall rarity has limited extensive and structured studies. However, there has been a gradual increase in the number of recent studies in the literature, including reviews and case reports. These Mini review [page 52] [Emergency Care Journal 2025; 21:13720] works focus on vital aspects such as diagnostic suspicion, thera- peutic management, and outcomes. In most cases, outcomes are favourable without significant long-term effects, as long as treat- ment is timely and appropriate. References 1. Lavalle S, Masiello E, Cocuzza S, et al. A pediatric Lemierre’s syndrome: a comprehensive literature review. Pediatric Rep 2024;16:201-213. 2. 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