CASES/YEAR
1,800,000 (US); 36,000,000 (Global)
OTHER NAMES
Generalized adenopathy; Cervical adenitis;
INCUBATION
Estimated: days to months;
INITIAL SYMPTOMS
Enlarged lymph node or nodes;
COMMENTS
FINDINGS:
In the evaluation of lymph nodes, one must distinguish acute vs. chronic and localized vs. generalized. A rubbery lymph node suggests lymphoma, and a hard one suggests cancer or actinomycosis. Tender lymph nodes suggest infection. An enlarged supraclavicular lymph node is one that deserves consideration for diagnostic biopsy. [ABX Guide] Biopsy lymph nodes if subclavian or scalene in location, if > 4 cm in size, or if rock-hard in consistency, especially if fixed to surrounding soft tissue. [Harrisons, p. 190] The 6 types of infectious lymphadenopathy are: 1.) regional; 2.) regional with breakdown of nodes; 3.) inguinal bubo formation; 4.) ulceroglandular; 5.) oculoglandular; and 6.) generalized. [PPID, p. 1322-3t] "In primary care settings, patients 40 years of age and older with unexplained lymphadenopathy have about a 4 percent risk of cancer versus a 0.4 percent risk in patients younger than age 40." [PMID 9803196] Lymph nodes commonly found in the groin are not considered abnormal. Lymph nodes >1 cm are considered abnormal. Malignant lymph nodes are generally painless and hard while infected lymph nodes are tender. Hematologic malignancies are typically soft. [Cecil, p. 1103-5] Lymphadenopathy is common in children; it is a benign process in about 80% of cases. [Cohen, p. 144]
DEFINITION:
The terms "generalized lymphadenopathy" (disease of the lymph nodes) and "widespread nonsuppurative lymphadenitis" (inflammation of the lymph nodes) are both used to refer to enlarged lymph nodes in the context of infectious diseases. [ID, p. 61; PPID, p. 1324; Guerrant, p. 935] In this database, "lymphadenitis" is used as the more specific term, referring to infected regional lymph nodes that may undergo suppuration or bubo formation. "Pain and tenderness typically distinguish lymphadenitis from lymphadenopathy." Causes of focal lymphadenitis are streptococcal infection, TB, nontuberculous mycobacteria, tularemia, plague, cat-scratch, primary syphilis, lymphogranuloma venereum, chancroid, and genital herpes. Causes of multifocal lymphadenitis are infectious mononucleosis, cytomegalovirus, toxoplasmosis, brucellosis, secondary syphilis, and disseminated histoplasmosis. [Merck Manual, p. 998]
NTM LYMPHADENITIS:
NTM (nontuberculous mycobacterial) lymphadenitis is a disease of children 1 to 5 years old. Nodes are usually unilateral and nontender. Fistulae and chronic drainage are complications of fine needle biopsy or I&D without complete surgical excision. "NTM cervical lymphadenitis is due to MAC in the majority of cases and treated primarily by surgical excision, with a greater than 90% cure rate." [ATS/IDSA Statement: Nontuberculous Mycobacterial Diseases]
IMMUNE RECONSTITUTION INFLAMMATORY SYNDROME
Painful, suppurative lymphadenopathy in the cervical, axillary, or inguinal nodes is characteristic of immune reconstitution syndrome in AIDS patients who are started on highly active therapy. [ATS/IDSA Statement: Nontuberculous Mycobacterial Diseases]
DIAGNOSTIC
Needle aspiration, incisional biopsy, or excisional biopsy, depending on the severity of the illness. [PPID, p. 1317] Biopsy if persist > 4 weeks, malignant appearance, or growing rapidly; CBC, HIV, RPR, CMV, EBV, & other based on hx; [ABX Guide]
SIGNS & SYMPTOMS
-
>fever
-
H lymphadenopathy
-
S lymphadenitis, acute
-
S lymphangitis
ENTRY
Inhalation, Ingestion, Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva), Animal Bite, Swimming, Sexual Contact
VECTOR
Fleas, Biting Flies, Lice, Mites, Mosquitoes, Ticks
SOURCE
Person-to-Person, Human Fecal-Oral, Fecally Contaminated Soil, Animal Excreta, Animal Tissue, Soil or Dust (Ingesting or Inhaling), Eating Contaminated Food, Eating Contaminated or Infected Meat, Eating Infected or Toxin-Containing Fish, Eating Contaminated Mollusks or Crustacean, Eating Unpasteurized Milk or Cheese, Eating Contaminated Produce, Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Birds and Poultry, Cattle, Goats and Sheep, Cats, Deer, Elk and Antelope, Dogs, Fish and Shellfish, Horses, Monkeys, Rabbits, Rodents, Swine, Human, Wild Animals
RISK FACTORS
- AIDS patients
- Cancer patients
REFERENCES FOR CASES/YEAR
1. (US) 1/20 X global cases/yr;
2. (Global) A Dutch study found a 0.6 percent annual incidence for unexplained lymphadenopathy. [PMID 9803196] Calculate: 0.6% X 6000 million = 36,000,000;