Causes of Cervical Lymphadenopathy
Cervical lymphadenopathy in adults is most commonly neoplastic rather than infectious, while in children aged 1-5 years, reactive viral lymphadenopathy and nontuberculous mycobacterial (NTM) infection are the predominant causes. 1, 2
Primary Etiologic Categories
Infectious Causes
- Viral infections are the most common cause in children, with reactive cervical lymphadenopathy occurring in up to 90% of children aged 4-8 years 3
- Bacterial infections including Staphylococcus aureus and Streptococcus pyogenes present with warmth, erythema, localized swelling, tenderness, and systemic signs like fever and tachycardia 1, 4
- Nontuberculous mycobacterial (NTM) lymphadenitis accounts for approximately 80% of culture-proven mycobacterial cervical adenitis, predominantly affecting children 1-5 years old, typically presenting as unilateral, non-tender cervical or submandibular nodes 1, 2
- Mycobacterium tuberculosis represents only ~10% of mycobacterial cervical lymphadenitis but requires distinction for treatment and public health tracking 2
- Epstein-Barr virus (EBV) is responsible for 27% of infectious causes in pediatric cervical lymphadenopathy 5
- Other viral pathogens include cytomegalovirus (4.3%) and parvovirus B19 (2.9%) 5
Malignant Causes
- Lymphomas are the most common malignancy causing cervical lymphadenopathy in both adults and children 5, 6
- Metastatic disease is a critical consideration in adults, particularly with supraclavicular or posterior cervical node involvement 7
- Malignancy risk increases significantly in adults over 40 years, with 38.6% of excisional biopsies in adults revealing malignant disease 6
Autoimmune and Inflammatory Causes
- Rosai-Dorfman-Destombes disease (RDD) presents classically with bilateral cervical lymphadenopathy, though 43% have extranodal disease 1
- Kawasaki disease must be considered in children with cervical lymphadenopathy ≥1.5 cm and fever ≥5 days, even without other classic features 2, 8
- Immune reconstitution inflammatory syndrome in HIV patients on antiretroviral therapy manifests as suppurative cervical, axillary, or inguinal lymphadenopathy 1, 4
Other Causes
- Disseminated Mycobacterium avium complex (MAC) in AIDS patients presents with fever of unknown origin and involves multiple organs, though pulmonary involvement is uncommon (2.5%) 1
- Iatrogenic and medication-related causes should be considered in the differential 7
Critical Red Flags for Malignancy
The following features mandate urgent workup for malignancy rather than empiric antibiotic treatment:
- Duration ≥2 weeks without significant fluctuation 1, 4
- Fixed, firm consistency or size >1.5 cm 1, 4
- Supraclavicular or posterior cervical location (malignancy rates of 100% and 66.7% respectively) 7, 6
- Ulceration of overlying skin 1
- Absence of infectious signs (no warmth, erythema, tenderness, fever) 1, 4
- Age >40 years, male sex, white race 7
- Systemic symptoms including unexplained weight loss and night sweats 7
Temporal and Contextual Clues
- Recent upper respiratory infection, dental problem, trauma, insect bites, travel, or animal exposure suggests infectious etiology 1
- Reactive lymphadenopathy from respiratory infections typically resolves within days of completing treatment or with resolution of symptoms 1, 2
- Development within days to weeks of an inciting event favors infectious cause over malignancy 1
Common Pitfalls to Avoid
Never prescribe empiric antibiotics without clear signs of bacterial infection (warmth, erythema, tenderness, fever, rapid onset), as this delays malignancy diagnosis and most adult neck masses are neoplastic. 1, 4
- Partial resolution on antibiotics may represent infection in an underlying malignancy and requires full workup 1, 4
- Incisional biopsy for suspected mycobacterial disease causes chronic fistula formation; complete excision is required 4, 8
- Mistaking NTM lymphadenitis for bacterial infection leads to inappropriate antibiotic use and delayed diagnosis 2