Mesenteric adenitis

Question 1

Mesenteric adenitis is an inflammation of the lymph nodes in the intestinal mesentery, and can mimic many other abdominal pathologies. Is this more common in adults or children?

Answer 1

• children

Question 2

What is the key acute abdomen presentation that mesenteric adenitis is often compared to because of the way it presents?

1 - diverticulitis
2 - appendicitis
3 - cholecystitis
4 - pancreatitis

Answer 2

2 - appendicitis

Question 3

Which of the following is NOT a risk for mesenteric adenitis?

1 - Age
2 - Immunocompromised
3 - Gender
4 - Prior gastrointestinal diseases

Answer 3

3 - Gender

Equally as likely in men and women

Question 4

Infection and autoimmune conditions are the 2 key primary causes of mesenteric adentisis, but which is most common?

Answer 4

• infection

Although less common, autoimmune conditions like systemic lupus erythematosus (SLE) or inflammatory bowel disease (IBD) may contribute to the development of mesenteric adenitis.

Question 5

Infection is the leading cause of mesenteric adenitis, generally following gastroenteritis. Which of the following has been linked to causing mesenteric adenitis?

1 - Yersinia enterocolitica
2 - Campylobacter jejuni
3 - Salmonella species
4 - Epstein-Barr virus (EBV)
5 - Cytomegalovirus (CMV)
6 - Adenoviruses
7 - All of the above

Answer 5

7 - All of the above

Viral and bacterial are the main cause

Question 6

Is viral or bacterial infection more common in mesenteric adenitis?

Answer 6

• viral organisms

Question 7

What is the most common mode of infection in mesenteric adenitis?

1 - respiratory infection
2 - STI
3 - GIT infection
4 - skin injury

Answer 7

3 - GIT infection

Typically due to contaminated food or water, BUT can be due to direct contact with an infected individual, or via airborne transmission.

Question 8

Once a patient is infected with an organism, the following steps occur:

Invasion and Replication
- replication in the intestinal epithelium where they replicate causing direct damage or inducing inflammation that damages tissue

Lymphatic Spread
- once infected the infection spreads through the intestinal epithelium and can be carried via lymphatic channels to regional mesenteric lymph nodes. Here they may cause bacteraemia and potential systemic infection.

Inflammation and Immune Response
- B and T cells are activated and proliferate, causing lymphadenopathy and then inflammation due to the infection causing acute abdominal pain.

Resolution or Progression
- Immune response in most patients eliminates the pathogens and lymph nodes return to normal. However, some patients develop abscess or systemic infection.

Question 9

In mesenteric adenitis, does the pain it causes typically move around?

Answer 9

• no

Typically isolated to right lower quadrant, and made worse with movement.

Good to distinguish from appendicitis, which begins centrally and move to right lower quadrant

Question 10

In mesenteric adenitis, is the pain mild, moderate or severe?

Answer 10

• can be a range from mild to severe

Question 11

Which of the following is common in mesenteric adenitis?

1 - nausea and vomiting
2 - diarrhoea or constipation
3 - anorexia
4 - coryzal symptoms following recent infection
5 - all of the above

Answer 11

5 - all of the above

Question 12

When comparing mesenteric adenitis with appendicitis, which typically has a higher temperature?

Answer 12

• mesenteric adenitis = high grade pyrexia (>39 degrees)
• appendicitis - low grade pyrexia (<38 degrees)

Question 13

Is lymphadenopathy always present upon examination in a patient presenting with mesenteric adenitis?

Answer 13

• no

BUT peritoneal irritation often causes rebound tenderness and guarding

Lymphadenopathy may also present elsewhere, such as cervical or axillary lymph nodes.

Question 14

Which of the following are considered atypical clinical findings in a patient with suspected mesenteric adenitis?

1 - left-sided abdominal pain
2 - back pain
3 - urinary symptoms
4 - diffuse systemic symptoms
5 - all of the above

Answer 14

5 - all of the above

Urinary symptoms = close structures may also become inflamed

Diffuse systemic symptoms = more likely in immunocompromised and elderly who are unable to fight infection

Question 15

All of the following blood tests should be performed in an attempt to diagnose mesenteric adenitis, but which is least important?

1 - CRP
2 - ESR
3 - LFTs
4 - FBC for leukocytosis

Answer 15

3 - LFTs

All others can identify inflammation and infection

Question 16

Are stool cultures useful in mesenteric adenitis?

Answer 16

• yes

To identify the potentially causative organism

Question 17

Are urinalysis useful in mesenteric adenitis?

Answer 17

• yes

To rule out UTI

Question 18

All of the following can be performed, but which of the following imaging modalities is often the 1st line imaging?

1 - Abdominal ultrasound
2 - Computed Tomography (CT)
3 - Magnetic Resonance Imaging (MRI)

Answer 18

1 - Abdominal ultrasound

Question 19

Which of the following can actually confirm a diagnosis of mesenteric adenitis?

1 - abdominal ultrasound
2 - blood biochemistry
3 - laparoscopy
4 - CT scan

Answer 19

3 - laparoscopy

Allows visualisation of the mesenteric adenitis

Question 20

Mesenteric adenitis in most cases is self limiting. Which 2 of the following are part of its symptomatic management?

1 - analgesia
2 - antibiotics
3 - fluids
4 - hospital admission

Answer 20

1 - analgesia
NSAIDs or paracetamol

3 - fluids
To combat dehydration

Antibiotic therapy only considering if causative organisms is bacterial (Yersinia, Campylobacter).

Hospital admission in severe cases that may require follow-up to ensure resolution