Mesenteric Lymphadenitis

ds00881_im02349_ans7_mesenterythu_jpg

  • inflammation of the mesenteric lymph nodes
  • Considered present if a cluster of three or more lymph nodes, each measuring 5 mm or greater, is detected in the right lower quadrant mesentery.
  • Can be acute or chronic
  • often difficult to differentiate from acute appendicitis

 

Pathophysiology

 

  • Microbial agents are thought to gain access to the lymph nodes via the intestinal lymphatics
  • Cause inflammation and, occasionally, suppuration.
  • A theory that swallowed pathogen-laden sputum may be the primary source of infection.
  • Fecal-oral transmission occurs in Y enterocoliticainfection and may present as a common source outbreak.

 

Etiology

  • Beta-hemolytic streptococcus, Staphylococcus species, Escherichia coli, Streptococcus viridans, Yersinia species (responsible for most cases currently), Mycobacterium tuberculosis, Giardia lamblia, and non– Salmonella typhoid.
  • Viruses, such as coxsackieviruses (A and B), rubeola virus, and adenovirus serotypes 1, 2, 3, 5, and 7, have also been implicated, Epstein-Barr virus (EBV), acute human immunodeficiency virus (HIV) infection, and cat scratch disease (CSD).

Gender & Age

  • males and females equally
  • Yersinia infection is more common in boys than in girls.
  • can occur in adults but is more common in children and adolescents younger than 15 years

 

History

  • Abdominal pain – Often right lower quadrant (RLQ) but may be more diffuse
  • Fever
  • Diarrhea
  • Malaise
  • Anorexia
  • Concomitant or antecedent upper respiratory tract infection
  • Nausea and vomiting (which generally precedes abdominal pain, as compared to the sequence in appendicitis)
  • History of ingestion of raw pork may be obtained in areas with endemic Yersinia (e.g., Belgium).

Physical Examination

  • Fever (38-38.5°C)
  • Flushed appearance
  • Right lower quadrant (RLQ) tenderness – Mild, with or without rebound tenderness
  • Voluntary guarding rather than abdominal rigidity
  • Rectal tenderness
  • Rhinorrhea
  • Hyperemic pharynx
  • Toxic appearance
  • Associated peripheral lymphadenopathy (usually cervical) in 20% of cases

 

Classification (by imaging)

Primary mesenteric adenitis is described as right-sided mesenteric lymphadenopathy that does not have an identifiable acute inflammatory process or demonstrates only mild (<5 mm) wall thickening of the terminal ileum. [1] The etiology may be an underlying infectious terminal ileitis.

 

Secondary mesenteric adenitis on imaging studies demonstrates lymphadenopathy that is associated with a specific, identifiable intraabdominal inflammatory process. [1] In the presence of clearly detectable terminal ileal thickening (e.g., Crohn disease, infectious ileitis), the mesenteric adenitis is considered secondary.
Differential diagnosis

  • Meckel diverticulitis
  • Intestinal duplication
  • Regional enteritis
  • Intussusception
  • Intestinal lymphoma
  • Other causes of acute abdomen (e.g., porphyria, sickle cell vaso-occlusive crises, cecal tumor, familial Mediterranean fever)
  • Acute Pyelonephritis
  • Appendicitis
  • Benign Neoplasm of the Small Intestine
  • Cholecystitis
  • Chronic Mesenteric Ischemia
  • Urinary Tract Infection (UTI) and Cystitis (Bladder Infection) in Females
  • Ectopic Pregnancy
  • Inflammatory Bowel Disease
  • Pelvic Inflammatory Disease
  • Urinary Tract Infection (UTI) in Males

Ix:

  • FBC, TWC>10 in at least 50% of cases.
  • RP for severe vomit
  • Serology can be supportive in diagnosis of etiologic agents such as Y enterocolitica.
  • UFEME to exclude UTI
  • Stool culture
  • Blood culture, septicemia

 

  • Computed tomography scanning
    • Enlarged mesenteric lymph nodes, with or without associated ileal or ileocecal wall thickening, and a normal appearing appendix.
  • Magnetic resonance imaging
  • Ultrasonography

 

Prognosis

 

  • Complete recovery can be expected without specific treatment. Death is rare.
  • But sepsis may have a fatal outcome.

 

Complications

  • Volume depletion and electrolyte imbalance in patients with severe diarrhea, nausea, and vomiting
  • Abscess formation
  • Peritonitis (rare)
  • Sepsis
  • risk of recurrence

 

Treatment

Given the predominance of Y enterocolitica, initial antibiotic selection from

  • trimethoprim-sulfamethoxazole (TMP-SMX)
  • third-generation cephalosporin
  • fluoroquinolones
  • aminoglycosides
  • doxycycline

These agents provide broad coverage for enteric pathogens.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s