Lymphadenopathy

Lymphadenopathy:  enlarged lymph nodes (generally larger than 1 cm).  for inguinal, its larger than  1.5 cm.  for epitrochlear  (located above the elbow cease on the medial side), its larger than .5 cm.

How do lymph nodes get enlarged? 
3 main ways:
1) reactive hyperplasia (cells in the lymph node react to an antigen / inflammation)
2) cells in the lymph node transform
3) malignant cells invade the lymph node

HISTORY:

• 2 main types of lymphadenopathy:  regional and generalized
• if regional: ask about regional symptoms (ex: cervical --> any pharyngeal symptoms, dental problems, hoarseness?)
• if generalized:  could be a number of things (infection, immunologic, metabolic, malignant); is often associated with splenomegaly
• fever, weight loss --> cancer, systemic infection, connective tissue disease
• rashes, arthralgias, pharyngeal symptoms, pet exposure --> connective tissue disease, viral illness, cat scratch fever
• contact with sheep --> brucellosis
• location --> coccidioidomycosis (west texas, desert west), histoplasmosis (mississippi river valley)
• animal bites --> Franciesella tularensis (rabbits), Pasteurella (domestic pet bites).

PHYSICAL EXAM:

• malignant:  hard, fixed, nontender, greater than 3 cm
• infectious: warm, erythematous, fluctuant
• reactive: discrete, rubbery, mobile
• red streaks from an inflammed node --> lyphangitis and lymphadenitis

Diagnosing:

• most are self-limited / benign
• can do monospot or strep screen to start, CBC, serology
• if supraclavicular --> can be serious and may need to do a biopsy
• supraclavicular or pulmonary symptoms --> chest xray
• various titers: EBV, toxoplasomosis, CMV,
• other serologic tests:  HIV antibodies, ANA, rheumatoid factor
• inguinal:  can do urethral or cervical cultures
• unusual cases (bites):  blood cultures
• US, CT, MRI can be done later on to delineate involved area
• anemia, thrombocytopenia, malignant cells on peripheral smear --> bone marrow examination

 Treatment:

• Cat scratch:  TMP/SMX
• Atypical mycobacteria: surgical excision + antituberculosis meds (Isoniazid, Rifampin, ethambutol)
• Lymphadenitis: treat with antibiotics that take care of strep and staph (Cephalosporin, Erythromycin, Dicloxacillin)
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