Description

• Acute bacterial infection of a cervical lymph node:
  • Often arising after a prior bacterial infection of the head or neck area
• Primarily a pediatric disease:
  • Becoming more common in adults owing to immunocompromised disease states (HIV, cancer, transplant patients)
• Any cervical node can become infected:
  • >50% of cases involve a submandibular node
  • Clinically manifests as warm, tender, swollen, erythematous node 3–6 cm in diameter
  • Nodes are usually mobile

Etiology

• 40–89% of cases are caused by Staphylococcus aureus (increasingly CA-MRSA) or group A β-hemolytic streptococcal (GAS) infection
• Group B streptococcus (GBS) can manifest as cellulitis/adenitis in infants
• Anaerobes:
  • Consider when associated with infections of the teeth or gingiva
• Tularemia (Francisella tularensis)
  • Febrile illness that occurs following contact with infected animals (rabbit, hamster, rodent)
  • Most cases in the U.S. occur in south-central region
  • Ulceroglandular syndrome (papular lesion in the drainage field of the inflamed lymph node)
• Cat-scratch disease (Bartonella henselae)
  • Symptoms begin within 1–4 wk following inoculation from bite or scratch
  • Fever and mild systemic symptoms occur in ∼30% of patients
  • Axillary nodes most commonly affected but 1 in 4 children may have isolated cervical nodes
  • Has indolent course but usually spontaneously resolves after 4–6 wk
• Nontuberculous mycobacteria (NTM)
  • Mycobacterium avium complex (MAC) most common cause
  • Usually presents as unilateral firm, nontender node that slowly enlarges over weeks (<4 cm)
  • Submandibular, jugulodigastric, parotid nodes most commonly affected
  • Typically seen in young children (<5 yr). Child may have a history of pica
• Tuberculosis
  • Uncommon in the U.S. but significant cause of cervical adenitis in other parts of the world
  • Suspect in patient with clinical symptoms compatible with TB, abnormal CXR, history of travel to endemic area
• Rare infectious causes
  • Yersinia pestis
  • Gram-negative bacilli
  • Anthrax
  • Pasteurella
• Noninfectious causes
  • Connective tissues disorders (consider if associated fever, rash, arthralgia)
  • Neoplasm (persistent or progressive symptoms, nontender node, weight loss, fever, fatigue)
  • Kawasaki disease (associated with fever for ≥5 d, rash, conjunctivitis, mucositis, edema of hands and feet)

• One of the most common causes of a neck mass in a child
• Overall, GAS and S. aureus most common causes
• In neonates, GBS and S. aureus most common
• GBS cellulitis–adenitis syndrome:
  • Infants are usually 3–7 wk of age, male, febrile, with submandibular or facial cellulitis, and an ipsilateral otitis media
  • 94% incidence of concurrent bacteremia
• S. aureus associated with a more indolent course and higher frequency of suppuration
• Viral infections generally result in bilateral lymphadenopathy

• Consider malignancy over infection in this population, especially in the absence of fever, leukocytosis, etc.
• Fixed, nontender, hard node most likely not cervical adenitis