What are the possible causes of intussusception in a 3-year-old child?

Possible Causes of Intussusception in a 3-Year-Old Child

The most common cause of intussusception in a 3-year-old child is idiopathic, often associated with viral infections that lead to mesenteric lymphoid hyperplasia, which can serve as a lead point for intestinal telescoping.

Common Etiologies of Intussusception in Children

Idiopathic Causes (Most Common)

• Lymphoid hyperplasia in the intestinal wall, typically following viral infections
  • Adenovirus is particularly significant, found in a high percentage of cases 1
  • Enterovirus has been documented as a trigger 2
  • Recent evidence suggests SARS-CoV-2 infection may be associated with intussusception 3, 4

Pathologic Lead Points (Less Common in Young Children)

• Meckel's diverticulum
• Intestinal polyps
• Lymphoma
• Intestinal duplication
• Foreign bodies
• Post-surgical adhesions

Age-Related Considerations

• In children under 2 years, idiopathic causes predominate
• In children over 2 years, adenovirus (particularly non-enteric types) appears to be a significant risk factor 1
• In children over 5-6 years, pathologic lead points become more common

Viral Infections and Intussusception

Viral infections are strongly associated with intussusception in children, with several mechanisms:

1. Mesenteric lymphoid hyperplasia: Viral infections cause enlargement of lymph nodes in the intestinal wall and mesentery, which can serve as lead points
2. Altered intestinal motility: Viral infections may disrupt normal peristalsis
3. Local inflammation: Viral-induced inflammation may contribute to the development of intussusception

Research has identified specific viral associations:

• Adenovirus was detected in 78.9% of intussusception cases in one study 1
• Enterovirus genome has been identified in mesenteric lymph nodes of affected children 2
• Recent case reports have documented intussusception in children with SARS-CoV-2 infection 3, 5, 4

Special Considerations

Vaccine-Associated Risk

While rare, there is a small association between rotavirus vaccination and intussusception:

• Previous rotavirus vaccine (Rotashield®) was withdrawn due to intussusception risk (approximately 1 case per 10,000 vaccine recipients) 6
• Current rotavirus vaccines have a much better safety profile:
  • RotaTeq® showed no significant increased risk in large trials (relative risk: 0.9; CI = 0.4-1.9) 6
  • RV1 (Rotarix®) similarly showed no increased risk compared to placebo 6

Hereditary Syndromes

In some cases, intussusception may be associated with hereditary conditions:

• Peutz-Jeghers syndrome (PJS) carries a 50-68% cumulative risk of intussusception during childhood 6
• Polyps >1.5-2 cm in size are particularly concerning as lead points for intussusception 6

Clinical Approach

When evaluating intussusception in a 3-year-old:

1. Assess for recent viral illness

   • Recent history of respiratory or gastrointestinal symptoms
   • Fever within the past 1-2 weeks

2. Consider pathologic lead points if:

   • Child is older (>2-3 years)
   • Recurrent episodes of intussusception
   • Intussusception at unusual locations
   • Family history of polyposis syndromes

3. Evaluate for warning signs of complications:

   • Peritoneal signs
   • Prolonged symptoms (>24 hours)
   • Bloody stools ("currant jelly")
   • Signs of intestinal ischemia

Conclusion

While most cases of intussusception in a 3-year-old are idiopathic and associated with viral-induced lymphoid hyperplasia, a thorough evaluation for potential pathologic lead points is warranted, especially in cases of recurrent intussusception or atypical presentation.