AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Mesenteric lymphadenitis refers to inflammation of the mesenteric lymph nodes. This process may be acute or chronic, depending on the causative agent. It causes a clinical presentation that is often difficult to differentiate from acute appendicitis.

Pathophysiology

Microbial agents are thought to gain access to the lymph nodes via the intestinal lymphatics. Organisms subsequently multiply and, depending on the virulence of the invading pathogen, elicit varying degrees of inflammation and, occasionally, suppuration.

Grossly, the lymph nodes are enlarged and often soft. The adjourning mesentery may be edematous, with or without exudates. If a contiguous primary source of infection (eg, the appendix) is present, evidence of inflammation is often apparent.

Microscopically, the lymph nodes show nonspecific hyperplasia and, in suppurative infection, necrosis with numerous pus cells.

Frequency

United States

The true incidence of this disease is not known, because it can be easily missed or mistaken for other diagnoses. The condition is generally thought to be common. Up to 20% of patients undergoing appendectomy have been found to have nonspecific mesenteric adenitis.

International

Frequency is similar to that of the United States. Yersinia enterocolitica infection has a geographic variation. This infection is most common in the temperate countries of Europe, North America, and Australia; it has been particularly noted in Eastern Europe.

Mortality/Morbidity

Mesenteric lymphadenitis generally is a benign disease, but patients with sepsis may have a fatal outcome.

Sex

The condition affects males and females equally. Yersinia infection is more common in boys than in girls.

Age

Mesenteric lymphadenitis can occur in adults but is more common in children and adolescents younger than 15 years.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

Onset and progression may be insidious or sometimes dramatic. Clinical features of associated organ involvement, such as enterocolitis or ileitis in Yersinia infection, may be present. Clinical presentations include the following:

• 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 (eg, Belgium).

Physical

No set of physical findings is pathognomonic of mesenteric lymphadenitis.

• Fever (38-38.5°C)
• Flushed appearance
• 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

Causes

• Numerous organisms have been cultured from mesenteric lymph nodes and blood.
• • Organisms include 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 been implicated.
• Mesenteric node involvement can also be part of infectious Epstein-Barr virus (EBV), acute human immunodeficiency virus (HIV) infection, and catscratch disease (CSD).
• The frequent association of this condition, especially in children with upper respiratory tract infection, has popularized a theory that swallowed pathogen-laden sputum may be the primary source of infection.
• Fecal-oral transmission occurs in Y enterocolitica infection and may present as a common source outbreak. This infection has also been associated with meat, milk, and water contamination. Rarely, person-to-person or zoonotic contacts with fecal carriers can lead to infection.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Meckel diverticulitis
Intestinal duplication
Regional enteritis
Intussusception
Intestinal lymphoma
Other causes of acute abdomen (eg, porphyria, sickle cell vasoocclusive crises, cecal tumor)

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• CBC count: Leucocytosis with WBCs exceeding 10,000/µL occurs in at least 50% of cases.
• Chemistries: - Findings are generally within reference ranges except in patients with severe nausea and vomiting who may present with metabolic alkalosis and azotemia.
• Serology can be supportive in diagnosis of etiologic agents such as Y enterocolitica. Serological tests tend to be delayed, and several antigens may have to be tested.
• Urinalysis may be useful to perform when the diagnosis is unclear and to exclude urinary tract infection.
• In patients who present with diarrheal symptoms, stool cultures should be performed.
• Blood culture: This is performed prior to prescribing antibiotics and in patients who have features of septicemia. Isolation of the organism from blood, lymph nodes, or other body fluids will help define appropriate therapy and guide further evaluation.

Imaging Studies

• Contrast computed tomography (CT) demonstrates enlarged mesenteric lymph nodes, with or without associated ileal or ileocecal wall thickening, and a normal appearing appendix. In mesenteric adenitis, lymph nodes tend to be larger, greater in number, and more widely distributed than in appendicitis. Rao et al specified the criterion of 3 or more nodes with a short-axis diameter of at least 5 clustered in the right lower quadrant. CT scanning is also important to exclude other differential diagnoses, especially acute appendicitis.
• Abdominal ultrasound scanning with Doppler scanning is a useful adjunct for excluding other differential diagnoses. For instance, ultrasonic demonstration of mural thickening of the terminal ileum plus mesenteric thickening is indicative of regional enteritis. Focal abdominal tenderness in response to transducer pressure is common. Ultrasound is often the preferred initial diagnostic procedure, especially in children with uncomplicated abdominal pain.

Procedures

• Lymph node specimen: In patients subjected to laparotomy, lymph nodes may show evidence of inflammation or suppuration, and culture may yield causative organism.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

The objective of medical management is to quickly identify patients who require surgical intervention (ie, for appendicitis) and to refer appropriately. Empiric, broad-spectrum antibiotics may be used in moderately to severely ill patients and should cover Yersinia strains, commonly causative in mesenteric adenitis. General supportive care includes hydration and pain medication after excluding acute surgical abdomen. Patients with mild, uncomplicated presentations do not require antibiotics, and supportive care generally suffices.

• Prehospital care
• • Prompt transfer of patients to a facility where an appropriate workup can be conducted is the most important prehospital goal.
  • Vascular access and saline infusion are beneficial for patients who are more ill and have volume depletion.
• Emergency department treatment
• • Carefully evaluate patients to exclude potentially life-threatening alternative diagnoses.
  • Initiate appropriate workup. Consult with a general surgeon when indicated.
• Hospital admission
• • Patients with volume depletion, significant electrolyte imbalance, and/or sepsis require hospital admission.
  • In instances for which diagnosis is not clear, inpatient observation and further workup may be appropriate.

Surgical Care

• Surgery is usually indicated in suppuration and/or abscess, with signs of peritonitis, or if acute appendicitis cannot be excluded with certainty.
• At laparotomy, the diagnosis is generally clear. An appendectomy should be performed in view of the tendency for recurrence of lymphadenitis and the difficulty in differentiating adenitis from appendicitis.

Consultations

Make early contact with a general surgeon while evaluating the patient to exclude etiologies that require urgent surgery.

Diet

No particular diet is recommended. Temporary withholding of oral intake may be necessary while nausea and vomiting resolve and initially until a definitive diagnosis is confirmed.

Activity

No restriction of activity is required.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Antibiotics are often started empirically in moderately to severely ill patients, using broad-spectrum antibiotics intended to cover the commonly associated pathogens. Antibiotic treatment should then be adjusted based on the sensitivity of the isolated pathogen. Treatment duration is variable based on the cause and severity of illness. For uncomplicated cases, antibiotic treatment is not necessary.

Drug Category: Antibiotics

When indicated, empiric antimicrobial therapy must be comprehensive and should cover the likely pathogens in the context of the clinical setting. Given the predominance of Y enterocolitica, initial antibiotic selection from trimethoprim-sulfamethoxazole (TMP-SMX), third-generation cephalosporins, fluoroquinolones, aminoglycosides, and doxycycline should be considered. These agents provide broad coverage for enteric pathogens.

Drug Name	Clindamycin (Cleocin)
Description	Lincosamide used for treatment of serious skin and soft tissue staphylococcal infections. Also effective against aerobic and anaerobic streptococci (except enterococci). Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, thus causing cessation of RNA-dependent protein synthesis.
Adult Dose	150-450 mg/dose PO q6-8h; not to exceed 1.8 g/d or 600-1200 mg/d IV/IM divided q6-8h, depending on degree of infection
Pediatric Dose	8-20 mg/kg/d PO as hydrochloride and 8-25 mg/kg/d as palmitate divided tid/qid or 20-40 mg/kg/d IV/IM divided tid/qid
Contraindications	Documented hypersensitivity, regional enteritis, ulcerative colitis, hepatic impairment, antibiotic-associated colitis
Interactions	Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects; antidiarrheals may delay absorption
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis

Drug Name	Ampicillin (Omnipen, Polycillin)
Description	Bactericidal activity against susceptible organisms. Alternative to amoxicillin when unable to take medication orally.
Adult Dose	250-500 mg PO q6h 500 mg to 1.5 g IM q4-6h 500 mg to 3 g IV q4-6h; not to exceed 12 g/d
Pediatric Dose	50-100 mg/kg/d PO divided q4-6h or 100-400 mg/kg/d IV/IM divided q4-6h
Contraindications	Documented hypersensitivity
Interactions	Probenecid and disulfiram elevate levels; allopurinol decreases effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction

Drug Name	Amoxicillin (Amoxil, Trimox)
Description	Interferes with synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria.
Adult Dose	500 mg PO q8h; not to exceed 3 g/d
Pediatric Dose	20-50 mg/kg/d PO divided q8h
Contraindications	Documented hypersensitivity
Interactions	Reduces the efficacy of oral contraceptives; aspirin and probenecid increase concentration
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Caution advised in patients with renal disease and seizure disorders

Drug Name	Ciprofloxacin (Cipro)
Description	Fluoroquinolone with activity against pseudomonads, streptococci, MRSA, Staphylococcus epidermidis, and most gram-negative organisms but no activity against anaerobes. Inhibits bacterial DNA synthesis and, consequently, growth. Trovafloxacin (Trovan) overcomes many of these limitations. Continue treatment for at least 2 d (7-14 d typical) after signs and symptoms have disappeared.
Adult Dose	250-500 mg PO bid or 200-400 mg IV q12h
Pediatric Dose	<18 years: Not recommended >18 years: Administer as in adults
Contraindications	Documented hypersensitivity
Interactions	Antacids, iron salts, and zinc salts may reduce serum levels; administer antacids 2-4 h before or after taking fluoroquinolones; cimetidine may interfere with metabolism of fluoroquinolones; ciprofloxacin reduces therapeutic effects of phenytoin; probenecid may increase ciprofloxacin serum concentrations; may increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT)
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	In prolonged therapy, perform periodic evaluations of organ system functions (eg, renal, hepatic, hematopoietic); adjust dose in renal function impairment; superinfections may occur with prolonged or repeated antibiotic therapy

Drug Name	Imipenem/cilastin (Primaxin)
Description	For treatment of multiple organism infections in which other agents do not have wide-spectrum coverage or are contraindicated because of potential for toxicity.
Adult Dose	Base initial dose on severity of infection and administer in equally divided doses; dose may range from 250-500 mg IV q6h; not to exceed 3-4 g/d; alternatively, 500-750 mg IM (or intra-abdominally) q12h
Pediatric Dose	<12 years: Not established; 15-25 mg/kg/dose IV q6h suggested for > 3 months Fully susceptible organisms: 15-25 mg/kg/dose IV q6h suggested for > 3 months; not to exceed 2 g/d Moderately susceptible organisms: 15-25 mg/kg/dose IV q6h suggested for > 3 months; not to exceed 4 g/d
Contraindications	Documented hypersensitivity
Interactions	Coadministration with cyclosporine may increase adverse CNS effects of both agents; coadministration with ganciclovir may result in generalized seizures
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Adjust dose in renal insufficiency; avoid use in children <12 years

Drug Name	Cefoxitin (Mefoxin)
Description	Second-generation cephalosporin indicated for gram-positive cocci and gram-negative rod infections. Infections caused by cephalosporin- or penicillin-resistant gram-negative bacteria may respond to cefoxitin.
Adult Dose	1-2 g IV q6-8h; in severe infections 1-2 g IV q4h
Pediatric Dose	Infants and children: 80-160 mg/kg/d IV divided q4-6h; higher doses for severe or serious infections; not to exceed 12 g/d
Contraindications	Documented hypersensitivity
Interactions	Probenecid may increase effects of; coadministration with aminoglycosides or furosemide may increase nephrotoxicity (closely monitor renal function)
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Bacterial or fungal overgrowth of nonsusceptible organisms may occur with prolonged use or repeated treatment; caution in patients with previously diagnosed colitis

Drug Name	Ticarcillin/clavulanate (Timentin)
Description	Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active growth. Antipseudomonal penicillin plus beta-lactamase inhibitor that provides coverage against most gram-positive bacteria, most gram-negative bacteria, and most anaerobes.
Adult Dose	3.1 g IV q4-6h; infuse over 30 min
Pediatric Dose	75 mg/kg IV q6h
Contraindications	Documented hypersensitivity; do not treat severe pneumonia, bacteremia, pericarditis, emphysema, meningitis, and purulent or septic arthritis with oral penicillin during acute stage
Interactions	Tetracyclines may decrease effects of ticarcillin; high concentrations of ticarcillin may physically inactivate aminoglycosides if administered in same IV line; effects when administered concurrently with aminoglycosides are synergistic; probenecid may increase penicillin levels
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Perform CBCs prior to initiation of therapy and at least weekly during therapy; monitor for liver function abnormalities by measuring AST and ALT during therapy; exercise caution in patients diagnosed with hepatic insufficiencies; perform urinalysis and BUN/creatinine determinations during therapy, and adjust dose if values become elevated; monitor blood levels to avoid possible neurotoxic reactions

Drug Name	Ampicillin/sulbactam (Unasyn)
Description	Drug combination of beta-lactamase inhibitor with ampicillin. Covers skin, enteric flora, and anaerobes. Not ideal for nosocomial pathogens.
Adult Dose	1.5 (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV/IM q6-8h; not to exceed 4 g/d sulbactam or 8 g/d ampicillin
Pediatric Dose	3 months to 12 years: 100-200 mg ampicillin/kg/d (150-300 mg Unasyn) IV divided q6h >12 years: Administer as in adult; not to exceed 4 g/d sulbactam or 8 g/d ampicillin
Contraindications	Documented hypersensitivity
Interactions	Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Inpatient care is indicated for patients with complications. When the diagnosis is not clear, admission for observation may be necessary.

Further Outpatient Care

• Schedule early outpatient follow-up visits to ensure complete resolution of symptoms.
• No further diagnostic tests are required for patients who recover completely. This is the case for most patients.

Complications

• Volume depletion and electrolyte imbalance in patients with severe diarrhea, nausea, and vomiting
• Abscess formation
• Peritonitis (rare)
• Sepsis
• In cases where the underlying pathogen is Y enterocolitica, some patients may develop arthralgias. These symptoms typically develop 1 month after the initial episode of diarrhea and usually resolve after 1-6 months. A rash on the legs and/or trunk, erythema nodosum, may also appear and is also self-limited.

Prognosis

• Prognosis is good. Typically, complete recovery can be expected without specific treatment. Death is rare.

Patient Education

• Explain the benign nature of the disease to patients; however, because there is a risk of recurrence, also explain that they must seek prompt medical attention in each instance to exclude other more emergent etiologies.
• In cases of Yersinia infection as the underlying infectious agent, instruct patients to avoid unpasteurized milk, raw pork (particularly chitterlings), and contaminated water.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Given the nonspecific signs and symptoms associated with mesenteric adenitis and the numerous associated differential diagnoses, the primary goal must be to avoid missing a potentially life-threatening condition (eg, acute appendicitis) and a delay in appropriate surgical and medical intervention.
• Conversely, in less complicated cases, surgery and/or ineffective antibiotics may be used without benefit to the patient if the diagnosis is made incorrectly.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Arrese M, Lopez F, Rossi R. Extrahepatic cholestasis attributable to tuberculous adenitis. Am J Gastroenterol. May 1997;92(5):912-3. [Medline].
• Asch MJ, Amoury RA, Touloukian RJ. Suppurative mesenteric lymphadenitis. A report of two cases and review of the literature. Am J Surg. Apr 1968;115(4):570-3. [Medline].
• Blattner RJ. Acute mesenteric lymphadenitis. J Pediatr. Mar 1969;DA - 19690327(3):479-81. [Medline].
• Campbell GL, Dennis TD. Plague and Other yersinia infections. In: Fauci AS et al, eds. Harrison's Principles of Internal Medicine. 14th ed. New York, NY: McGraw-Hill;1998:975-983.
• Currie B. Yersinia enterocolitica. Pediatr Rev. Jul 1998;19(7):250; discussion 251. [Medline].
• Daly JM, Adams JT, et al. Abdominal wall, Omentum, Messentery and Retroperitoneum. In: Schwarttz ST et al, eds. Principles of Surgery. 7th ed. New York, NY: McGraw-Hill Health Professions Div;1999:1574-1575.
• Faller DV. Diseases of Lymph nodes and Spleen. In: Bennet JC et al, eds. Cecil Textbook of Medicine. WB Saunders;1996:1968-970.
• Feldman M. ''.
• Kelly CS, Kelly RE Jr. Lymphadenopathy in children. Pediatr Clin North Am. Aug 1998;45(4):875-88. [Medline].
• Morris Jr JG. Yersinia infections. In: Bennet JC et al, eds. Cecil textbook of Medicine. WB Saunders;1996:1661.
• Rao PM, Rhea JT, Novelline RA. CT diagnosis of mesenteric adenitis. Radiology. 1997;202:145-149.
• Schrock TR. Appendicitis. Gastrointestinal and Liver Disease, 6th Edition. 1998;1782.
• Sivit CJ. Imaging children with acute right lower quadrant pain. Pediatr Clin North Am. Jun 1997;44(3):575-89. [Medline].
• Zganjer M, Roic G, Cizmic A. Infectious ileocecitis--appendicitis mimicking syndrome. Bratisl Lek Listy. 2005;106(6-7):201-2.

Article Last Updated: Aug 17, 2006