Lymph Node Infections

Thanks to Dr. Jeffrey D. Cirillo for his outline and presentation, which was the basis of this post.

The most common lymph node swelling is due to infection (lymphadenitis).

• Groin, armpit, neck, under jaw/ears
• Oncological vs. microbiological
  • Acute onset (infection) or gradual onset (cancer)
  • Painful (infection) or painless (cancer -usually)
  • Resolve in a few weeks (viral, self-limiting)
  • Fever, night sweats, weight loss (infection, serious)
  • Red, discolored, black/blue (infection, serious)

    

  • Continually increasing, no other indicator (cancer)

• Lymphadenitis –Common Causes
  • Streptococcus, Staphylococcus (local skin)
  • Mononucleosis (cervical)
  • Tuberculosis (mediastinal, hilaradenopathy)
  • Tularemia (regional, cervical)
  • Yersinia (cervical, abdominal)
  • Salmonella (general)
  • Rubella (auricular, posterior cervical, occipital)
  • Atypical mycobacterial infections (submandibular)
  • Histoplasmosis(mediastinal, hilar)
  • Chlamydia (conjunctivitis)
  • Toxoplasmosis (general)
  • Brucella(cervical, rare)

• Diagnostic Approach
  • History (chronic vs. acute, other indicator).
  • Blood work (liver, kidney, CBC, differential)
    • Lymphocytes, neutrophils (infection, leukemia)
    • Monocytes (infection)
    • Eosinophils(cancer, parasitic infection)
  • Chest X-ray (armpit/neck nodes)
  • Platelet count (certain cancers)
  • Liver-spleen scan

• Tularemia-F. Tularensis
  • Rabbits, summer, arthropods
  • Gram negative, coccobacilli, facultative intracellular pathogen, survives in phagocytes
  • Tularemia I S/S-regional LAD with ulceration 3-5 days, painless rash
  • Tularemia II S/S-infection of spleen, liver, bone, lung, granulomas
  • Dx-poorly staining, four-fold increase in titers, persistent Ab, ELISA and Cx positive
  • Tx-aminoglycosides
  • Prevention-limited exposure to rabbits, cook meat well, live attenuated vaccine

• Bubonic Plague-Yerninia Pestis
  • Rats, fleas, human to human (droplets)
  • Gram negative rod, facultative intracellular, anaerobe, capsulated
  • Interaction with host cells via surface adhesins
  • S/S-LAD with buboes, painful (2-6 days after flea bite), fever, confusion, back and limb pain
  • Dx-blood cx, low level bacteremia, bubo aspirate, sputum (pneumonic), direct fluorescent microscopy, serology, blood agar cx
  • Tx-tetracycline or streptomycin, gentamicin/doxy/cipro
  • Prevention-vaccine, rodent control, isolation/quarantine

• Brucellosis-Brucella spp.
  • Livestock, humans are accidental hosts, ingestion (milk), contact/inhalation
  • Gram negative bacilli
  • Spreads via lymph, disseminated form causes bacteremia (RES), phagocytosis (granulomas)
  • S/S-FUO days to months after exposure (cyclical), malaise, aches, liver dysfunction, granulomas, LAD, osteomyelitis, endocarditis
  • Chronic S/S-(one year of illness) fatigue, aches and pains, depression, anxiety, occasional fever
  • Dx-Cx (blood or tissue), titers >1:160 is presumptive
  • Tx-Doxy and rifampin 6-12 weeks
  • Prevention-cattle vaccination, pasteurization of milk, vaccine high risk population

• Chlamydia-C. Trachomatis
  • STI/STD, can also cause cervicitis, urethritis, trachoma, conjunctivitis
  • Gram negative cocci/oval, obligate intracellular pathogen
  • S/S-(lymphogranuloma), first stage-small painless vesicular lesion, fever, headache, and myalgia; second stage-LAD, fever, headache, myalgia, buboes, proctitis, ulcers or elephantiasis
  • Dx-Cytology and Cx-iodine staining inclusions, ELISA (LPS), NAT
  • Tx-tetracycline, erythromycin, sulfonamides
  • Prevention-safe sex habits, treat partners too

• Toxoplasmosis-Toxoplasma gondii
  • Domestic cat, humans accidental hosts
  • Obligate intracellular parasite
  • ⅓ risk of fetal infection with primary maternal infection in pregnancy, death higher in 1st trimester, more infections in 3rd trimester
  • Fetus/newborn infections-70-90% are asymptomatic at birth
  • Classic triad of symptoms: Chorioretinitis, Hydrocephalus, Intracranial calcifications
  • S/S include fever, rash, hepatosplenomegaly, microcephaly, seizures, jaundice, thrombocytopenia, lymphadenopathy
  • Initially asymptomatic infants are still at high risk of developing abnormalities, especially chorioretinitis
  • Dx-maternal IgG testing indicates past infection, cx-placenta umbilical cord, infant serum, newborn serologies with IgM/IgA
  • Tx-adults-sulfadiazine and pyrimethamine plus leucovorin; pregnant women-spiramycin; fetus dx-treat mother spiramycin, pyrimethamine, and sulfadiazine, leucovorin rescue for pyrimethamine; symptomatic newborns-pyrimethamine, leucovorin, and sulfadiazine for 12 months; asymptomatic newborns-same as symptomatic newborns, tx one month
  • Prevention-cook meat completely, freezing meat, washing hands/utensils/dishes contact raw meat; environment don’t drink untreated water, keep away from soil used by cats, wear gloves when changing litter box, keep cats indoors, don’t get a new cat or handle unknown cats while pregnant