Henoch-Schönlein Purpura in Children

Introduction to Henoch-Schönlein Purpura in Children

Henoch-Schönlein Purpura (HSP), also known as IgA Vasculitis, is the most common form of systemic vasculitis in children. It is characterized by a tetrad of clinical manifestations:

  • Palpable purpura (without thrombocytopenia)
  • Arthralgia or arthritis
  • Abdominal pain
  • Renal involvement

Key features of HSP include:

  • Acute, self-limited disorder that primarily affects small vessels
  • IgA1-dominant immune deposits in affected organs
  • Predominantly affects children, with peak incidence between 4-6 years
  • Generally benign course, but can have serious complications, particularly renal involvement

Understanding the nuances of HSP in children is crucial for timely diagnosis, appropriate management, and prevention of complications.

Epidemiology of Henoch-Schönlein Purpura in Children

Henoch-Schönlein Purpura is the most common vasculitis in childhood, with distinct epidemiological characteristics:

  • Incidence:
    • Estimated at 10-20 cases per 100,000 children per year
    • Varies by geographic location and ethnicity
  • Age distribution:
    • 90% of cases occur in children under 10 years of age
    • Peak incidence between 4-6 years
    • Can occur in infants and adolescents, but rare after 18 years
  • Gender: Slight male predominance, with male-to-female ratio of 1.2-1.8:1
  • Seasonal variation:
    • More common in autumn and winter months
    • Suggests possible link to infectious triggers
  • Geographic distribution:
    • Reported worldwide
    • Higher incidence in Asian and Caucasian populations
  • Recurrence: Occurs in about 30% of children, usually within 4 months of initial episode

The epidemiology of HSP underscores its importance as a common childhood vasculitis, with potential for significant morbidity if not recognized and managed appropriately.

Etiology of Henoch-Schönlein Purpura in Children

The exact cause of Henoch-Schönlein Purpura remains unknown, but it is believed to result from an aberrant immune response to various triggers in genetically susceptible individuals:

Potential Triggers:

  • Infections:
    • Upper respiratory tract infections (most common)
    • Group A streptococcus
    • Viral infections: Parvovirus B19, Epstein-Barr virus, hepatitis viruses
  • Medications:
    • Antibiotics (particularly penicillins and cephalosporins)
    • Non-steroidal anti-inflammatory drugs (NSAIDs)
  • Vaccinations: Rarely reported as potential triggers
  • Food allergies: Suggested in some cases
  • Insect bites

Pathogenesis:

  • IgA immune complex deposition in small vessel walls
  • Activation of alternative complement pathway
  • Increased production of pro-inflammatory cytokines (IL-1, TNF-α, IL-6)
  • Neutrophil infiltration and vessel damage

Genetic Factors:

  • HLA associations: HLA-DRB1*01, HLA-DRB1*11, HLA-DRB1*14 linked to increased susceptibility
  • Polymorphisms in genes involved in IgA production and glycosylation
  • Familial clustering observed in some cases

The current understanding is that HSP results from an interplay of environmental triggers and genetic susceptibility, leading to an abnormal immune response and IgA-mediated small vessel vasculitis.

Clinical Presentation of Henoch-Schönlein Purpura in Children

The clinical presentation of Henoch-Schönlein Purpura in children is characterized by its classic tetrad, though not all features may be present simultaneously:

1. Cutaneous Manifestations:

  • Palpable purpura: Hallmark feature, present in nearly all cases
  • Distribution: Typically on lower extremities and buttocks
  • Appearance: Begins as erythematous maculopapules that evolve into purpuric lesions
  • May be accompanied by edema, especially of hands, feet, and scrotum

2. Joint Involvement:

  • Occurs in 60-84% of cases
  • Usually presents as arthralgia, sometimes with overt arthritis
  • Typically affects ankles and knees
  • Self-limiting, resolves without permanent damage

3. Gastrointestinal Manifestations:

  • Present in 50-75% of children
  • Abdominal pain: Most common GI symptom
  • Other symptoms: Nausea, vomiting, gastrointestinal bleeding
  • Rare complications: Intussusception, bowel perforation, pancreatitis

4. Renal Involvement:

  • Occurs in 20-60% of cases
  • Usually mild and self-limiting
  • Manifestations range from microscopic hematuria to nephrotic syndrome
  • Typically develops within 4-6 weeks of disease onset

Other Less Common Manifestations:

  • Scrotal pain and swelling (in boys)
  • Pulmonary involvement (rare): Diffuse alveolar hemorrhage
  • Central nervous system involvement (rare): Headaches, seizures, behavioral changes

Constitutional Symptoms:

  • Low-grade fever
  • Fatigue
  • Anorexia

The clinical presentation can vary widely between patients and may evolve over the course of the disease. The order of appearance of symptoms is variable, and not all components of the classic tetrad may be present in every case.

Diagnosis of Henoch-Schönlein Purpura in Children

Diagnosis of Henoch-Schönlein Purpura is primarily clinical, based on the characteristic presentation. However, laboratory tests and sometimes imaging studies are used to support the diagnosis and assess organ involvement:

Diagnostic Criteria:

According to the European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Paediatric Rheumatology European Society (EULAR/PRINTO/PRES) criteria, diagnosis requires:

  • Mandatory criterion: Palpable purpura (without thrombocytopenia)
  • Plus at least one of the following:
    1. Diffuse abdominal pain
    2. Histopathology showing typical leukocytoclastic vasculitis or proliferative glomerulonephritis with predominant IgA deposits
    3. Arthritis or arthralgia
    4. Renal involvement (hematuria and/or proteinuria)

Laboratory Studies:

  • Complete blood count: Usually normal, may show mild leukocytosis or anemia
  • Inflammatory markers: ESR and CRP may be elevated
  • Coagulation studies: Normal (to exclude other causes of purpura)
  • Renal function tests: BUN, creatinine
  • Urinalysis: To detect hematuria or proteinuria
  • Stool guaiac test: To detect occult blood in stool
  • Serum IgA levels: May be elevated

Imaging Studies:

  • Abdominal ultrasound: If severe abdominal pain or suspicion of intussusception
  • Renal ultrasound: In cases of significant renal involvement

Histopathology:

  • Skin biopsy: Leukocytoclastic vasculitis with IgA deposits (if diagnosis is uncertain)
  • Renal biopsy: Considered in cases of severe or persistent renal involvement

Differential Diagnosis:

  • Other causes of purpura: Thrombocytopenia, coagulation disorders
  • Other vasculitides: ANCA-associated vasculitis, polyarteritis nodosa
  • Acute appendicitis (in cases with predominant abdominal pain)
  • Systemic lupus erythematosus
  • Acute rheumatic fever

While the diagnosis is often straightforward in typical cases, atypical presentations may require more extensive workup. The key is to recognize the characteristic purpura and associated symptoms, while excluding other potential causes.

Treatment of Henoch-Schönlein Purpura in Children

Treatment of Henoch-Schönlein Purpura in children is primarily supportive, as the disease is usually self-limiting. However, management strategies vary based on the severity of symptoms and organ involvement:

General Supportive Care:

  • Adequate hydration
  • Rest during the acute phase
  • Monitoring for complications

Symptom-Specific Management:

  1. Cutaneous and Joint Symptoms:
    • Acetaminophen or NSAIDs for pain relief
    • Elevation of affected limbs to reduce edema
  2. Gastrointestinal Symptoms:
    • Antacids or proton pump inhibitors for abdominal pain
    • Antiemetics if significant nausea/vomiting
    • Surgical consultation if severe GI complications (e.g., intussusception)
  3. Renal Involvement:
    • Close monitoring of renal function and urine output
    • ACE inhibitors or ARBs for persistent proteinuria

Pharmacological Interventions:

  1. Corticosteroids:
    • Not routinely recommended for uncomplicated cases
    • Considered for severe gastrointestinal symptoms, orchitis, or severe joint pain
    • Role in preventing renal disease is controversial
  2. Immunosuppressants:
    • Reserved for severe or persistent renal involvement
    • Options include cyclophosphamide, azathioprine, mycophenolate mofetil
  3. Other therapies:
    • Colchicine: Sometimes used for persistent purpura
    • Dapsone: Occasionally used for chronic cutaneous disease

Management of Severe Cases:

  • Hospitalization may be required for:
    • Severe abdominal pain or gastrointestinal bleeding
    • Significant renal involvement
    • Inability to maintain oral hydration
  • Multidisciplinary approach involving rheumatology, nephrology, and gastroenterology as needed

Follow-up:

  • Regular monitoring of blood pressure and urinalysis for at least 6 months
  • Long-term follow-up for patients with significant renal involvement

Treatment decisions should be individualized based on the severity of symptoms and the presence of complications. While most cases resolve spontaneously, careful monitoring and timely intervention are crucial to prevent and manage potential complications, particularly renal involvement.

Prognosis of Henoch-Schönlein Purpura in Children

The prognosis of Henoch-Schönlein Purpura in children is generally favorable, with most cases resolving spontaneously. However, the course and long-term outcomes can vary:

Short-term Prognosis:

  • Acute phase: Usually lasts 4-6 weeks
  • Skin manifestations: Typically resolve within 3-4 weeks
  • Joint symptoms: Generally improve within 1-2 weeks
  • Gastrointestinal symptoms: Usually resolve within a few days to weeks

Long-term Prognosis:

  • Overall: Excellent in most cases
  • Recurrence: Occurs in about 30% of children, usually within 4 months of initial episode
  • Renal outcomes:
    • Most important determinant of long-term prognosis
    • 1-2% of children may develop end-stage renal disease
    • Risk factors for poor renal outcomes include:
      • Severe proteinuria at onset
      • Persistent proteinuria beyond 1 year
      • Hypertension
      • Older age at onset (>10 years)

Follow-up Recommendations:

  • Regular urinalysis and blood pressure monitoring for at least 6 months
  • Long-term follow-up for patients with history of significant renal involvement
  • Annual check-ups recommended for several years after apparent resolution

Potential Long-term Complications:

  • Chronic kidney disease or hypertension in a small percentage of cases
  • Rarely, chronic gastrointestinal issues or bowel strictures

Prognostic Factors:

  • Age: Children under 3 years generally have milder disease
  • Severity of initial presentation: Particularly renal and gastrointestinal involvement
  • Recurrent episodes: May increase risk of renal sequelae

While Henoch-Schönlein Purpura is typically a self-limiting condition in children with an excellent prognosis, the potential for renal complications necessitates careful monitoring and follow-up. Early recognition and appropriate management of renal involvement are crucial for optimizing long-term outcomes.



Henoch-Schönlein Purpura in Children
  1. What is the primary cause of Henoch-Schönlein Purpura (HSP)?
    An abnormal immune system response, often triggered by infections
  2. Which age group is most commonly affected by HSP?
    Children between 2 and 11 years old
  3. What is the classic tetrad of symptoms in HSP?
    Palpable purpura, arthritis/arthralgia, abdominal pain, and renal involvement
  4. Which skin manifestation is characteristic of HSP?
    Palpable purpura, typically on the lower extremities and buttocks
  5. What percentage of HSP cases occur in children under 10 years old?
    Approximately 90%
  6. Which season has the highest incidence of HSP?
    Winter and early spring
  7. What is the male to female ratio in HSP occurrence?
    1.5:1 (boys are more commonly affected)
  8. Which diagnostic criteria are used for HSP in children?
    EULAR/PRINTO/PRES criteria
  9. What is the most common gastrointestinal symptom in HSP?
    Abdominal pain
  10. Which joint is most frequently affected in HSP-related arthritis?
    Knee joint
  11. What percentage of HSP patients develop renal involvement?
    30-50%
  12. What is the most common renal manifestation in HSP?
    Hematuria
  13. Which lab test is specific for diagnosing HSP?
    There is no specific diagnostic test for HSP
  14. What is the gold standard for diagnosing HSP nephritis?
    Renal biopsy
  15. Which immunoglobulin is deposited in the small vessels in HSP?
    IgA
  16. What is the typical duration of an acute HSP episode?
    4-6 weeks
  17. Which medication is commonly used to treat severe abdominal pain in HSP?
    Corticosteroids
  18. What percentage of children with HSP experience recurrence?
    20-30%
  19. Which organ involvement is most concerning for long-term prognosis in HSP?
    Kidney involvement
  20. What is the recommended duration of urinalysis monitoring after HSP diagnosis?
    6 months
  21. Which condition should be considered in the differential diagnosis of HSP?
    Acute post-streptococcal glomerulonephritis
  22. What is the role of ANCA testing in HSP?
    To rule out ANCA-associated vasculitis
  23. Which infection is most commonly associated with triggering HSP?
    Group A streptococcal infection
  24. What is the recommended first-line treatment for mild HSP?
    Supportive care and NSAIDs for pain relief
  25. Which complication of HSP requires immediate surgical intervention?
    Intussusception
  26. What is the typical pattern of joint involvement in HSP?
    Oligoarticular and migratory
  27. Which imaging modality is most useful in diagnosing HSP-related intussusception?
    Abdominal ultrasound
  28. What is the role of plasma exchange in HSP treatment?
    It may be considered in severe cases with significant renal involvement
  29. Which medication may be used to prevent recurrent HSP episodes?
    Colchicine
  30. What is the long-term prognosis for most children with HSP?
    Excellent, with complete recovery in the majority of cases


Further Reading

Further Reading

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