Overview
Definition:
Henoch-Schönlein purpura (HSP), also known as IgA vasculitis, is the most common childhood vasculitis, characterized by palpable purpura, arthritis/arthralgia, abdominal pain, and glomerulonephritis
Intussusception is a significant gastrointestinal complication of HSP.
Epidemiology:
HSP typically affects children aged 3-10 years, with a bimodal peak incidence in preschool and school-aged children
Males are more commonly affected
Intussusception occurs in approximately 1-3% of children with HSP, most frequently in those with more severe abdominal symptoms.
Clinical Significance:
Recognizing intussusception as a complication of HSP is crucial for prompt diagnosis and management, as it can lead to bowel ischemia, perforation, and potentially life-threatening outcomes if delayed
Early identification aids in appropriate therapeutic interventions and improved patient prognosis.
Clinical Presentation
Symptoms:
Colicky, severe abdominal pain, often periumbilical or in the right lower quadrant
Vomiting, which may be bilious
Hematochezia or melena, indicating gastrointestinal bleeding
Passage of a palpable, sausage-shaped mass in the abdomen is a classic, though not always present, sign
Fever may be present.
Signs:
Abdominal tenderness, guarding, and rebound tenderness suggesting peritonitis
Palpable purpura, typically on the lower extremities and buttocks
Arthritis or arthralgia, commonly affecting the knees and ankles
Renal involvement manifesting as hematuria and proteinuria
Signs of hypovolemia or shock if significant blood loss or bowel compromise occurs.
Diagnostic Criteria:
Diagnosis of HSP is typically based on clinical findings and histopathology
Modified European League Against Rheumatism (EULAR)/Pediatric Rheumatology International Trials Organisation (PRINTO)/Pediatric Rheumatology European Society (PReS) criteria often include: palpable purpura plus at least one of the following: abdominal pain, biopsy showing IgA deposition in the vessel wall, arthritis, or renal involvement
For intussusception in HSP, the diagnosis is usually clinical and confirmed by imaging.
Diagnostic Approach
History Taking:
Detailed history of abdominal pain characteristics (onset, duration, severity, location, radiation)
Associated symptoms like vomiting, diarrhea, or bleeding
Recent history of upper respiratory tract infection, which can be a trigger for HSP
History of purpura, arthritis, or hematuria
Family history of vasculitis or kidney disease.
Physical Examination:
Thorough abdominal examination to assess for tenderness, masses, distension, and signs of peritoneal irritation
Careful examination of the skin for characteristic purpura
Assessment of joints for swelling and tenderness
Evaluation for renal tenderness
Measurement of vital signs to detect shock or dehydration.
Investigations:
Abdominal ultrasonography is the imaging modality of choice for diagnosing intussusception, showing a target sign and lack of peristalsis
CT scan may be useful if ultrasound is inconclusive or complications are suspected
Complete blood count (CBC) may show anemia due to bleeding or leukocytosis
Coagulation profile is important
Urinalysis to assess for hematuria and proteinuria
Stool occult blood test for gastrointestinal bleeding
Serum creatinine and blood urea nitrogen (BUN) to assess renal function
Biopsy of purpuric lesions can show leukocytoclastic vasculitis with IgA deposition, confirming HSP.
Differential Diagnosis:
Other causes of abdominal pain and purpura in children, including idiopathic thrombocytopenic purpura (ITP), meningococcemia, viral exanthems with purpura, leukemia, and non-HSP vasculitis
Other causes of intussusception, such as Meckel's diverticulum or lymphoid hyperplasia, though less common in the context of systemic HSP symptoms.
Management
Initial Management:
Intravenous fluid resuscitation for dehydration
Pain management with analgesics
Correction of any electrolyte imbalances
Close monitoring of vital signs and abdominal examination for signs of peritonitis or bowel compromise.
Medical Management:
Corticosteroids (e.g., oral prednisolone 1-2 mg/kg/day) are the mainstay for managing HSP, particularly for gastrointestinal symptoms and arthritis
They may help reduce inflammation and the risk of intussusception
However, their role in preventing intussusception is debated
Immunosuppressive agents like azathioprine or cyclophosphamide may be considered for severe or refractory cases, especially with significant renal involvement.
Surgical Management:
Surgical intervention for intussusception in HSP is indicated if there are signs of bowel perforation, peritonitis, or gangrene, or if non-operative reduction (e.g., hydrostatic or pneumatic enema under radiologic guidance) fails or is contraindicated
Laparotomy may be required for manual reduction, resection of ischemic bowel, or appendectomy if the appendix is intussuscepted.
Supportive Care:
Nutritional support should be provided, especially if oral intake is compromised
Regular monitoring of hydration status and urine output
Education of parents regarding the disease course, potential complications, and warning signs to seek immediate medical attention.
Complications
Early Complications:
Bowel ischemia and infarction due to vasculitic inflammation and intussusception
Bowel perforation leading to peritonitis
Acute kidney injury
Severe gastrointestinal bleeding.
Late Complications:
Chronic kidney disease or end-stage renal disease in a subset of patients with severe renal involvement
Recurrent episodes of HSP or intussusception
Adhesions leading to bowel obstruction in the long term following surgery.
Prevention Strategies:
While direct prevention of intussusception in HSP is not fully established, prompt and adequate treatment of HSP with corticosteroids may reduce the incidence and severity of gastrointestinal manifestations, potentially including intussusception
Early recognition and management of abdominal pain suggestive of intussusception are critical to prevent ischemic complications.
Prognosis
Factors Affecting Prognosis:
The presence and severity of renal involvement are the most significant determinants of long-term prognosis in HSP
Age at onset, extent of purpura, and presence of gastrointestinal bleeding also influence outcomes
Intussusception, especially if complicated by ischemia or perforation, can lead to significant morbidity.
Outcomes:
Most children with HSP have a self-limited course with complete recovery
Renal involvement is the main concern for long-term morbidity
With timely diagnosis and management, including surgical intervention for complicated intussusception, outcomes can be favorable
Untreated or severe intussusception can lead to significant morbidity or mortality.
Follow Up:
Regular follow-up appointments are essential, especially for patients with renal involvement, to monitor for progression of kidney disease
Patients who have experienced intussusception should be monitored for signs of recurrence or long-term gastrointestinal issues
Urine and blood tests are typically performed periodically to assess renal function.
Key Points
Exam Focus:
Intussusception is a critical gastrointestinal complication of HSP, occurring in 1-3% of affected children
The hallmark symptom is colicky abdominal pain, often accompanied by vomiting and hematochezia
Ultrasonography is the diagnostic modality of choice
Prompt recognition and management, including surgical intervention if necessary, are vital to prevent ischemic complications.
Clinical Pearls:
Always consider HSP in a child presenting with palpable purpura and abdominal pain, especially if there is associated arthritis or renal involvement
Be vigilant for intussusception in any child with HSP who develops severe, colicky abdominal pain and vomiting
A high index of suspicion is key for early diagnosis.
Common Mistakes:
Mistaking intussusception in HSP for simple gastroenteritis or other common causes of abdominal pain, leading to delayed diagnosis and treatment
Underestimating the severity of abdominal pain in HSP
Not performing or ordering appropriate imaging (ultrasound) for suspected intussusception
Delaying surgical consultation when indicated for complicated intussusception.