HSP Summary

Definition

  • Most common vasculitis of childhood
  • Ages 3-15 years
  • Affects small vessels
  • Classic tetrad presentation

Classic Tetrad

  • Palpable purpura rash
  • Abdominal pain
  • Arthritis/arthralgia
  • Glomerulonephritis

Common Triggers

  • Post-URTI (especially strep)
  • Immune-mediated
  • Possible drug triggers
  • Unknown exact etiology

Diagnosis

  • Clinical diagnosis
  • Biopsy shows IgA deposition
  • Urinalysis essential
  • Rash always present

Management

  • Most resolve spontaneously
  • Symptomatic treatment
  • Steroids for severe cases
  • Monitor renal function

Prognosis

  • 94% recovery in children
  • 89% recovery in adults
  • 33% recurrence rate
  • Usually milder recurrences

Henoch-Schonlein Purpura (HSP)

The most common vasculitis of childhood

Introduction

Henoch-Schonlein purpura (HSP) is the most common vasculitis of childhood, occurring predominantly between the ages of 3 and 15 years, and affecting the small vessels. HSP is characterised by the classic tetrad of rash, abdominal pain, arthritis/arthralgia, and glomerulonephritis.

Causes

Unknown Etiology

The underlying cause of HSP remains unknown. It is an immune-mediated vasculitis, with a variety of infectious and chemical triggers having been proposed as a cause.

Common Triggers

  • Many cases occur after upper respiratory tract infections (URTI)
  • Especially streptococcal infections
  • Some cases may be drug-related (penicillin, cefaclor, minocycline, hydralazine, phenytoin)
  • Relationship to drugs is unclear

Diagnosis

Clinical Diagnosis

HSP is usually diagnosed clinically, based on characteristic features in the history and physical examination; laboratory tests are non-specific.

Classic Tetrad

Rash

  • Palpable purpura, typically non-blanching
  • Can occur anywhere but concentrated on lower extremities
  • Present in all patients with HSP

Abdominal Pain

  • Colicky abdominal pain
  • May be associated with GI bleeding
  • Can mimic surgical abdomen

Arthritis/Arthralgia

  • Migratory polyarthritis
  • Most commonly affects knees and ankles
  • Non-deforming

Glomerulonephritis

  • Hematuria and proteinuria
  • Can progress to renal failure
  • Most serious long-term complication

Diagnostic Confirmation

Biopsy Findings

In patients with unusual presentations (pulmonary hemorrhage, headaches, seizures followed by rash), a biopsy of affected organ (skin or kidney) will show IgA deposition, which confirms the diagnosis of HSP.

Other Tests

Essential Tests

  • Urinalysis in all patients to assess renal involvement
  • Serum creatinine and electrolytes if abnormal urinalysis

Supportive Tests

  • Serum IgA levels (may be elevated but not specific)
  • Coagulation studies (to exclude other causes)
  • ANA, ANCA, complement levels (typically negative, helps differentiate)

Imaging

  • Ultrasound for severe abdominal pain (evaluate intussusception or perforation)
  • Ultrasound for testicular pain and swelling

Management

Natural History

Most cases of HSP resolve spontaneously (usually within 4 weeks). Complete recovery occurs in 94% of children and 89% of adults. One third of patients may have a recurrence within 4 months (generally milder).

Symptomatic Management

Pain Management

  • Joint pain: ibuprofen or paracetamol (equally efficacious)
  • Mild to moderate abdominal pain: paracetamol and supportive care

Corticosteroid Use

  • Oral prednisolone for:
    • Scrotal involvement
    • Severe edema
    • Severe abdominal pain
  • IV corticosteroids if abdominal pain with nausea/vomiting
  • Surgical consultation for severe abdominal pain

Renal Involvement Management

Moderate Renal Disease

  • Specific treatment considered for:
    • Nephrotic-range proteinuria
    • Declining renal function
  • IV corticosteroids (pulse dosing) recommended

Severe Renal Disease

  • Rapidly progressive nephritis requires:
    • Corticosteroids
    • Immunosuppressants
    • Plasmapheresis
  • Renal transplant may be required for end-stage renal disease

Complications

Pulmonary

  • Pulmonary haemorrhage

Gastrointestinal

  • GI haemorrhage
  • Intussusception
  • Bowel ischemia

Renal

  • Renal impairment with deterioration of function
  • End-stage renal disease
  • Hypertension

Neurological

  • CNS complications (headaches, seizures)
  • Intracranial hemorrhage

Ocular

  • Ocular complications (keratitis, uveitis)

Recurrence Risk

Recurrences are more common in patients with nephritis. One third of patients may have a recurrence within 4 months, but subsequent episodes are generally milder.