Cervical lymphadenitis is the most common regional lymphadenitis among children and is associated most commonly with pharyngitis caused by group A streptococcus (see Chapter 103), respiratory viruses, and Epstein-Barr virus (EBV). Other common infectious causes of cervical lymphadenitis include Bartonella henselae (cat-scratch disease) and nontuberculous mycobacteria.
EBV is the primary cause of infectious mononucleosis, a clinical syndrome characterized by fever, fatigue and malaise, cervical or generalized lymphadenopathy, tonsillitis, and pharyngitis. EBV, a member of the herpesvirus family, infects B lymphocytes and is spread by salivary secretions. After primary infection, EBV is maintained latently in multiple episomes in the cell nucleus of resting B lymphocytes and establishes lifelong infection that remains clinically inapparent. Most persons shed EBV intermittently, with approximately
F. tularensis (ulceroglandular tularemia)
B. henselae (cat-scratch disease)
Y. pestis (plague) Nocardia (nocardiosis) Cutaneous diphtheria (Corynebacterium diphtherial) Cutaneous coccidioidomycosis (Coccidioides immitis) Cutaneous histoplasmosis (Histoplasma capsulatum)
Cutaneous leishmaniasis Cutaneous sporotrichosis (S. schenckii) 20% of healthy individuals shedding EBV at any given time. Cytomegalovirus (CMV), Toxoplasma gondii, adenoviruses, hepatitis B virus, hepatitis C virus, and initial human immunodeficiency virus (HIV) infection, known as acute retroviral syndrome, can cause an infectious mononucleosis-like syndrome with lymphadenopathy.
The cause of cat-scratch disease is B. henselae, a small, pleomorphic, gram-negative bacillus that stains with Warthin-Starry silver stain. B. henselae causes apparently asymptomatic bacteremia in cats, and kittens under 1 year of age are more likely to harbor the organism. B. henselae is transmitted to humans by bites and scratches, which may be minor. B. henselae also causes bacillary angiomatosis and peliosis hepatis in persons with HIV infection (see Chapter 125).
Nontuberculous mycobacteria are ubiquitous in soil, vegetation, dust, and water. Mycobacterium species commonly causing lymphadenitis in children includes M. avium complex,
M. scrofulaceum, and M. kansasii. M. tuberculosis uncommonly causes cervical lymphadenitis.
Acute cervical lymphadenitis as a complication of group A streptococcal infection parallels the incidence of streptococcal pharyngitis (see Chapter 103). Many cases are caused by
S. aureus. EBV and CMV are ubiquitous, with most infections occurring in young children, who may often be asymptomatic or only mildly symptomatic. Risk factors for other specific causes of lymphadenopathy may be indicated by past medical and surgical history; preceding trauma; exposure to animals; contact with persons infected with tuberculosis; sexual history; travel history; food and ingestion history, especially of undercooked meat or unpasteurized dairy products; and current medications.
The exact location and detailed measurement of the size, shape, characteristics, and number of involved nodes should be noted, including their consistency, mobility, tenderness, warmth, fluctuance, firmness, and adherence to adjacent tissues. Important findings include presence or absence of dental disease, oropharyngeal or skin lesions, ocular disease, other nodal enlargement, and any other signs of systemic illness, including hepatosplenomegaly and skin lesions.