Henoch-Schonlein purpura

Background

• Abbreviation: HSP
• Classical triad of non-thrombocytopenic palpable purpura, abdominal pain, arthritis
• Most common vasculitis in childhood (usually 2-11 yr)
  • Small vessel
  • IgA mediated
  • 5% of cases associated with intussusception (abdominal vasculitis)
  • Most cases preceded by a URI
  • 95% recover completely after 3-4wk
• Progression to renal insufficiency is feared complication (5-15% in children)
  • Presentation in adults is often worse, with persisting renal insufficiency in 30-50%
  • Adults may require more aggressive treatment with steroids +/- cyclophosphamide though evidence of benefit is lacking

Clinical Presentation

Typical purpura on lower legs and buttocks

Classic

Palpable Purpura

Symptoms may develop over the course of days to weeks and vary in order of presentation

1. Rash: palpable purpura
   • Often begins with erythematous, macular, or urticarial wheals, progressing into the typical ecchymoses, petechiae, and palpable purpura (see picture)
   • Typically appears in crops, symmetrically distributed, and located primarily in gravity/pressure-dependent areas (e.g. lower extremities, buttocks)
2. Acute abdominal pain
   • Typically diffuse and colicky
   • May have blood in the stool (massive bleeding is rare)
3. Arthritis/arthralgia
   • Migratory, usually involves knees/ankles
4. Nephritis/renal disease
   • (~50% of the time)
   • Hematuria +/- proteinuria

Rare manifestations

• Melena, hematemesis, hepatosplenomegaly
• Headache, seizures
• Fever
• Non-pitting edema of the extremities and face
• Nephrotic syndrome
  • Long-term mortality directly related to renal involvement

Differential Diagnosis

Pediatric Abdominal Pain

0–3 Months Old

• Emergent
  • Necrotizing Enterocolitis
  • Volvulus
  • Testicular torsion
  • Inguinal hernia
    • Incarcerated hernia
  • Trauma
  • Pyloric stenosis
  • Toxic megacolon
  • Hirschsprung's Disease
• Nonemergent
  • Constipation
  • Acute Gastroenteritis
  • Colic

3 mo–3 y old

• Emergent
  • Intussusception
  • Testicular Torsion
  • Trauma
  • Volvulus
  • Appendicitis
  • Toxic megacolon
  • Vaso-occlusive crisis
• Nonemergent
  • Acute Gastroenteritis
  • Constipation
  • Urinary tract infection
  • Henoch-Schonlein purpura

3 y old–adolescence

• Emergent
  • Appendicitis
  • DKA
  • Vaso-occlusive crisis
  • Toxic ingestion
  • Testicular Torsion
  • Ovarian Torsion
  • Ectopic Pregnancy
  • Trauma
  • Toxic megacolon
  • Inflammatory bowel disease
  • Gastric ulcer disease
  • Ovarian cyst
  • Pregnancy
  • Pancreatitis
  • Cholecystitis
  • Intussusception (to age 6)
• Nonemergent
  • Constipation
  • Acute Gastroenteritis
  • Nonspecific viral syndrome
  • Streptococcus pharyngitis
  • Urinary tract infection
  • Pneumonia
  • Renal Stone
  • Henoch-Schonlein purpura
  • Inflammatory bowel disease
  • Vulvovaginitis

Petechiae/Purpura (by cause)

• Abnormal platelet count and/or coagulation
  • Septicemia
  • Idiopathic thrombocytopenic purpura (ITP)
  • Hemolytic uremic syndrome
  • Leukemia
  • Coagulopathies (e.g. hemophilia)
  • Henoch-Schonlein Purpura (HSP)
  • Acute hemorrhagic edema of infancy (AHEI)
• Hypersensitivity vasculitis
• Primary vasculitides
  • Wegener's
  • Microscopic polyangiitis
  • Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
• Secondary vasculitides
  • Henoch-Schonlein purpura
  • Connective tissue disorder
    • Systemic lupus erythematosus
  • Scurvy
  • Infectious disease
    • Hepatitis B
    • Hepatitis C
• Trauma

Causes of Glomerulonephritis

• Poststreptococcal glomerulonephritis
• Hemolytic-uremic syndrome
• Henoch-Schonlein purpura
• IgA nephropathy
• Lupus nephritis
• Alport syndrome
• Goodpasture syndrome
• Paraneoplastic

Diagnosis

Work-Up

• CBC (normal)
• Chemistry
• PT/PTT (normal)
• UA (hematuria, proteinuria)
• Stool guaiac (positive in >50%)
• Consider abdominal ultrasound if concerns for intussusception (at higher risk)

Evaluation

• Usually a clinical diagnosis
  • Rule out other possible causes (see differential diagnosis)
• In patients with an incomplete or unusual presentation, no lab test is diagnostic but biopsy of the affected organ (e.g. skin or kidney) with predominantly immunoglobulin A (IgA) deposition supports diagnosis

Treatment

• Supportive
• NSAIDs for pain, may worsen renal disease or GI disease
• Consider prednisone 1mg/kg/day for severe arthralgias, abdominal or scrotal disease

Disposition

• Outpt management for most with rheumatology follow up
• Recurrence rate of up to 33%

See Also

• Pediatric Rashes