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Emergency and Acute Medicine – Cervical Adenitis
Overview
Cervical adenitis is an acute bacterial infection of a cervical lymph node, most often arising after a preceding bacterial infection of the head or neck. It is primarily a pediatric condition but is increasingly recognized in adults, particularly those who are immunocompromised (HIV, malignancy, transplant recipients). Any cervical node may be involved, though more than 80% of pediatric cases affect the submandibular or deep cervical nodes, commonly the jugulodigastric node just below the mandibular angle. Cervical lymph nodes serve as the final common drainage pathway for the head and neck. Initial lymphadenopathy reflects hyperplasia and lymphocytic infiltration; progression to lymphadenitis occurs when bacteria proliferate within the lymphatic system, leading to neutrophil activation, pus formation, abscess development, and a clinically warm, tender, erythematous, swollen node.
Causative Factors
Approximately 70% of cases are due to group A β-hemolytic Streptococcus, 20% to Staphylococcus aureus, and about 10% to viral or other bacterial causes. Community-acquired MRSA infections are increasingly common, particularly in children, who have high colonization and invasive disease rates. Mycobacterial causes include tuberculosis (scrofula), typically a chronic posterior cervical lymphadenitis with strongly positive PPD and nonsurgical management, and atypical mycobacteria such as Mycobacterium avium complex, which usually presents as chronic submandibular or anterior cervical lymphadenitis and is treated surgically. Bartonella henselae causes catscratch disease, a subacute lymphadenitis with minimal systemic symptoms that usually resolves spontaneously over 4–6 weeks. Anaerobes should be considered with dental or gingival infections. Rare pathogens include gram-negative bacilli, Yersinia pestis, group B Streptococcus, Francisella tularensis, alpha-streptococcus, and Bacillus anthracis.
In neonates, group B Streptococcus and S. aureus predominate. Group B streptococcal cellulitis–adenitis syndrome presents in infants 3–7 weeks old with fever, submandibular or facial cellulitis, ipsilateral otitis media, and a high rate of bacteremia. Viral infections often cause bilateral adenopathy. In older adults, malignancy should be considered, particularly with hard, fixed, nontender nodes and absence of systemic infection signs.
Clinical Presentation
Patients typically present with a unilateral, enlarged, tender cervical lymph node with overlying warmth and erythema. The node is initially firm and may become fluctuant as suppuration develops. Fever may be present, along with malaise, and irritability in infants and children. A concurrent head or neck infection is common, including pharyngitis, tonsillitis, peritonsillar abscess, otitis media or externa, dental infection, impetigo, or scalp infection.
History and Examination
Key history includes timing of onset, associated fever, weight loss or rash, exposure or travel history, and comorbidities or birth history in infants. Physical examination requires a complete head and neck assessment with attention to airway patency and overall clinical appearance.
Evaluation Strategy
Cervical adenitis is primarily a clinical diagnosis. Identification of a primary head or neck infection source is essential. If no local source is found, tuberculosis exposure should be considered and systemic or viral illness evaluated. Laboratory studies are unnecessary when a clear, treatable source is identified. Blood cultures are reserved for toxic-appearing patients, and full sepsis evaluation is required in neonates. When etiology is unclear, adjunct testing such as CBC with differential, Monospot, throat cultures, and targeted serologies (EBV, CMV, toxoplasmosis) may be useful. Imaging with chest radiograph, lateral neck film, or Panorex can help identify occult sources or deep space infection; chest radiograph may screen for tuberculosis. Ultrasound can distinguish cystic from solid lesions and detect deep abscesses, while CT or MRI helps delineate deep space infections or congenital masses. Fluctuant nodes should undergo needle aspiration for Gram stain, acid-fast stain, and aerobic, anaerobic, mycobacterial, and fungal cultures, except when tuberculosis is suspected, due to risk of sinus tract formation.
Alternative Diagnoses
Consider reactive lymphadenopathy from viral infections (adenovirus, rhinovirus, enterovirus, EBV, HSV, VZV, CMV), mumps, rubella, rubeola, Kawasaki disease, Kikuchi disease, PFAPA syndrome, toxoplasmosis, congenital cysts (branchial cleft, thyroglossal duct cyst, cystic hygroma), malignancy (leukemia, lymphoma, rhabdomyosarcoma, thyroid carcinoma), and systemic inflammatory diseases such as lupus or sarcoidosis.
Management Principles
Airway monitoring is essential if significant neck swelling is present. Treatment targets the underlying source of infection, with empiric coverage for group A Streptococcus and S. aureus; MRSA coverage should be considered if there is poor response to standard therapy. All fluctuant nodes require aspiration. Oral agents such as cephalexin, cefadroxil, or amoxicillin–clavulanate are commonly effective. Clindamycin or amoxicillin–clavulanate is preferred when dental or anaerobic sources are suspected. CA-MRSA may be treated with clindamycin or TMP-SMX, recognizing increasing resistance; toxic patients may require IV vancomycin or linezolid. Antibiotic therapy should continue for at least 10 days. Adjunctive measures include warm compresses and analgesia.
Disposition and Follow-Up
Admission is indicated for neonates, airway compromise, toxic appearance, immunocompromised patients, inability to tolerate oral intake, or failure of outpatient therapy. Most patients can be discharged on oral antibiotics with mandatory re-evaluation in 48–72 hours. Patients should return immediately for worsening symptoms, abscess formation, voice changes, dyspnea, or systemic illness. Referral to ENT or dentistry is based on the infection source, and concerning features for malignancy or congenital anomalies warrant specialist evaluation.
Clinical Insights
Cervical adenitis is a clinical diagnosis most often caused by group A Streptococcus or Staphylococcus aureus. Unilateral, warm, tender, erythematous lymphadenopathy is characteristic. Consider group B Streptococcus in young infants and MRSA in cases not improving with standard therapy. Disposition decisions should be guided by overall clinical status rather than node size alone.
Overview
Cervical adenitis is an acute bacterial infection of a cervical lymph node, most often arising after a preceding bacterial infection of the head or neck. It is primarily a pediatric condition but is increasingly recognized in adults, particularly those who are immunocompromised (HIV, malignancy, transplant recipients). Any cervical node may be involved, though more than 80% of pediatric cases affect the submandibular or deep cervical nodes, commonly the jugulodigastric node just below the mandibular angle. Cervical lymph nodes serve as the final common drainage pathway for the head and neck. Initial lymphadenopathy reflects hyperplasia and lymphocytic infiltration; progression to lymphadenitis occurs when bacteria proliferate within the lymphatic system, leading to neutrophil activation, pus formation, abscess development, and a clinically warm, tender, erythematous, swollen node.
Causative Factors
Approximately 70% of cases are due to group A β-hemolytic Streptococcus, 20% to Staphylococcus aureus, and about 10% to viral or other bacterial causes. Community-acquired MRSA infections are increasingly common, particularly in children, who have high colonization and invasive disease rates. Mycobacterial causes include tuberculosis (scrofula), typically a chronic posterior cervical lymphadenitis with strongly positive PPD and nonsurgical management, and atypical mycobacteria such as Mycobacterium avium complex, which usually presents as chronic submandibular or anterior cervical lymphadenitis and is treated surgically. Bartonella henselae causes catscratch disease, a subacute lymphadenitis with minimal systemic symptoms that usually resolves spontaneously over 4–6 weeks. Anaerobes should be considered with dental or gingival infections. Rare pathogens include gram-negative bacilli, Yersinia pestis, group B Streptococcus, Francisella tularensis, alpha-streptococcus, and Bacillus anthracis.
In neonates, group B Streptococcus and S. aureus predominate. Group B streptococcal cellulitis–adenitis syndrome presents in infants 3–7 weeks old with fever, submandibular or facial cellulitis, ipsilateral otitis media, and a high rate of bacteremia. Viral infections often cause bilateral adenopathy. In older adults, malignancy should be considered, particularly with hard, fixed, nontender nodes and absence of systemic infection signs.
Clinical Presentation
Patients typically present with a unilateral, enlarged, tender cervical lymph node with overlying warmth and erythema. The node is initially firm and may become fluctuant as suppuration develops. Fever may be present, along with malaise, and irritability in infants and children. A concurrent head or neck infection is common, including pharyngitis, tonsillitis, peritonsillar abscess, otitis media or externa, dental infection, impetigo, or scalp infection.
History and Examination
Key history includes timing of onset, associated fever, weight loss or rash, exposure or travel history, and comorbidities or birth history in infants. Physical examination requires a complete head and neck assessment with attention to airway patency and overall clinical appearance.
Evaluation Strategy
Cervical adenitis is primarily a clinical diagnosis. Identification of a primary head or neck infection source is essential. If no local source is found, tuberculosis exposure should be considered and systemic or viral illness evaluated. Laboratory studies are unnecessary when a clear, treatable source is identified. Blood cultures are reserved for toxic-appearing patients, and full sepsis evaluation is required in neonates. When etiology is unclear, adjunct testing such as CBC with differential, Monospot, throat cultures, and targeted serologies (EBV, CMV, toxoplasmosis) may be useful. Imaging with chest radiograph, lateral neck film, or Panorex can help identify occult sources or deep space infection; chest radiograph may screen for tuberculosis. Ultrasound can distinguish cystic from solid lesions and detect deep abscesses, while CT or MRI helps delineate deep space infections or congenital masses. Fluctuant nodes should undergo needle aspiration for Gram stain, acid-fast stain, and aerobic, anaerobic, mycobacterial, and fungal cultures, except when tuberculosis is suspected, due to risk of sinus tract formation.
Alternative Diagnoses
Consider reactive lymphadenopathy from viral infections (adenovirus, rhinovirus, enterovirus, EBV, HSV, VZV, CMV), mumps, rubella, rubeola, Kawasaki disease, Kikuchi disease, PFAPA syndrome, toxoplasmosis, congenital cysts (branchial cleft, thyroglossal duct cyst, cystic hygroma), malignancy (leukemia, lymphoma, rhabdomyosarcoma, thyroid carcinoma), and systemic inflammatory diseases such as lupus or sarcoidosis.
Management Principles
Airway monitoring is essential if significant neck swelling is present. Treatment targets the underlying source of infection, with empiric coverage for group A Streptococcus and S. aureus; MRSA coverage should be considered if there is poor response to standard therapy. All fluctuant nodes require aspiration. Oral agents such as cephalexin, cefadroxil, or amoxicillin–clavulanate are commonly effective. Clindamycin or amoxicillin–clavulanate is preferred when dental or anaerobic sources are suspected. CA-MRSA may be treated with clindamycin or TMP-SMX, recognizing increasing resistance; toxic patients may require IV vancomycin or linezolid. Antibiotic therapy should continue for at least 10 days. Adjunctive measures include warm compresses and analgesia.
Disposition and Follow-Up
Admission is indicated for neonates, airway compromise, toxic appearance, immunocompromised patients, inability to tolerate oral intake, or failure of outpatient therapy. Most patients can be discharged on oral antibiotics with mandatory re-evaluation in 48–72 hours. Patients should return immediately for worsening symptoms, abscess formation, voice changes, dyspnea, or systemic illness. Referral to ENT or dentistry is based on the infection source, and concerning features for malignancy or congenital anomalies warrant specialist evaluation.
Clinical Insights
Cervical adenitis is a clinical diagnosis most often caused by group A Streptococcus or Staphylococcus aureus. Unilateral, warm, tender, erythematous lymphadenopathy is characteristic. Consider group B Streptococcus in young infants and MRSA in cases not improving with standard therapy. Disposition decisions should be guided by overall clinical status rather than node size alone.
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