Bacterial Cervical Lymphadenitis

Bacterial cervical lymphadenitis is acute bacterial infection of one or more cervical lymph nodes, most often in children, causing tender, enlarged nodes that may suppurate.

• Staphylococcus aureus and Group A Streptococcus cause most acute unilateral cases. Anaerobes are involved in dental and tonsillar sources.
• It often follows a throat, ear or skin infection, and dental disease.
• Subacute or chronic lymphadenitis (more than 2 weeks) suggests non-tuberculous mycobacteria, Bartonella henselae (cat scratch disease), tuberculosis, toxoplasmosis or other causes.
• Methicillin-resistant Staphylococcus aureus is increasingly implicated.
• Peak age is under 5 years.

Findings are local and systemic.

• Rapid onset of a tender, warm, firm node, usually unilateral (submandibular or anterior cervical), 2 cm or more.
• Overlying erythema and fluctuation signal abscess formation.
• Fever, malaise, reduced appetite, neck stiffness or torticollis.
• Source: tonsillitis, pharyngitis, otitis, impetigo or dental infection.
• Differential diagnosis: viral lymphadenitis, mycobacterial lymphadenitis, cat scratch disease, Kawasaki disease, lymphoma, leukaemia, branchial cleft cyst, thyroglossal duct cyst, cystic hygroma, parotitis, retropharyngeal abscess and deep neck infection.
• Complications: abscess formation, spontaneous rupture and sinus formation, cellulitis, deep neck space infection, bacteraemia, septic thrombophlebitis of the jugular vein (Lemierre syndrome), airway compromise and scarring.

Diagnosis is clinical, with ultrasound for abscess.

• History: duration, fever, source, animal contact (cat), tuberculosis exposure, immunisation.
• Examination of throat, ears, teeth, scalp, skin and other node groups. Measure the node.
• Full blood count, C-reactive protein, blood culture if febrile and unwell.
• Neck ultrasound to differentiate cellulitis from abscess and to guide aspiration.
• Throat swab, culture of aspirated pus (with Gram stain, acid-fast stain and culture).
• Tuberculin skin test or interferon-gamma release assay, Bartonella serology and HIV test in chronic or non-responsive cases.
• Computed tomography with contrast if deep neck abscess or airway involvement is suspected.
• Biopsy if the node is hard, fixed, rapidly enlarging, over 3 cm, or persists beyond 4 to 6 weeks.

Antibiotics for cellulitis, drainage for abscess.

• Supportive: analgesia, antipyretics, fluids, warm compresses, and rest.
• Pharmacological, oral for mild disease: amoxicillin-clavulanate 25 mg/kg (amoxicillin component) twice daily or cefalexin 12.5 to 25 mg/kg four times daily for 7 to 10 days. Clindamycin 10 mg/kg three times daily if penicillin allergy or suspected MRSA; cotrimoxazole is an alternative for MRSA at 4 mg/kg of trimethoprim twice daily.
• Intravenous for severe or systemic illness: flucloxacillin 25 to 50 mg/kg every 6 hours, or ampicillin-sulbactam 50 mg/kg every 6 hours, or clindamycin 10 mg/kg every 8 hours, or vancomycin 15 mg/kg every 6 hours for MRSA. Switch to oral when improving, for a total of 10 to 14 days.
• Paracetamol 15 mg/kg every 6 hours.
• Procedures: ultrasound-guided needle aspiration or incision and drainage for fluctuant abscess (usually over 2 to 3 cm); surgical excision for non-tuberculous mycobacterial adenitis (antibiotics alone are less effective).
• Treat the source (dental extraction, tonsillectomy for recurrent tonsillitis).
• Cat scratch disease: azithromycin 10 mg/kg on day 1, then 5 mg/kg for 4 days, for large nodes.
• Special groups: infants under 3 months, immunocompromised children and those with airway symptoms need admission.
• Red flags: airway compromise, drooling, trismus, torticollis, rapidly enlarging nodes, systemic sepsis, hard fixed nodes and persistence beyond 4 weeks.
• Follow-up: review in 48 to 72 hours. If no improvement, image and consider abscess, atypical mycobacteria or malignancy. Review at 4 to 6 weeks.