How is Henoch-Schönlein Purpura (HSP) investigated and treated?

Investigation and Management of Henoch-Schönlein Purpura (HSP)

Henoch-Schönlein purpura is diagnosed based on finding palpable purpura plus at least one of the following: renal involvement (hematuria and/or proteinuria), abdominal pain, or arthritis, and management should be tailored to specific organ involvement with special attention to renal manifestations which determine long-term prognosis. 1

Diagnostic Approach

• HSP is an acute, systemic, immune complex-mediated, leukocytoclastic vasculitis characterized by a triad of palpable purpura (without thrombocytopenia), abdominal pain, and arthritis 2
• Diagnosis is clinical and based on finding palpable purpura plus at least one of: renal involvement (hematuria/proteinuria), abdominal pain, or arthritis 1
• More than 90% of cases occur in children younger than 10 years; however, adults with this condition are more likely to experience complications and have worse renal prognosis 2, 3
• Most patients have an antecedent upper respiratory illness, which may serve as a triggering factor 2
• Other potential triggers include viral, bacterial and parasitic infections, drugs, toxins, systemic diseases and cancer, which should be investigated 3

Clinical Manifestations

• All patients develop a purpuric rash (100%), predominantly on the lower limbs 2, 4
• Approximately 75% develop arthritis or arthralgia, typically migratory polyarthralgias 2, 5
• 60-65% develop abdominal pain, which may be severe and can be complicated by intussusception 2, 5
• 40-50% develop renal disease, ranging from mild hematuria to severe nephritis 2
• Less common manifestations include pulmonary, cardiac, genital, and neurological symptoms 3

Laboratory Investigation

• HSP is a clinical diagnosis, but laboratory tests should be performed to assess organ involvement and rule out other conditions 1
• First-line laboratory tests should include:
  • Complete blood count to rule out thrombocytopenia 1
  • Comprehensive metabolic panel to assess renal function 1
  • Urinalysis to detect hematuria and/or proteinuria 1
  • Inflammatory markers (ESR, CRP) may be elevated 2
• Skin biopsy (if diagnosis is uncertain) will show leukocytoclastic vasculitis with IgA deposits 4
• Renal biopsy may be indicated in patients with significant proteinuria, hematuria, or declining renal function 1

Treatment Approach

General Management

• Because HSP spontaneously resolves in 94% of children and 89% of adults, supportive treatment is the primary intervention 2
• Supportive care includes adequate hydration, pain management, and monitoring for complications 2
• A low-antigen-content (LAC) diet may improve symptoms and laboratory abnormalities when strictly followed for 4-8 weeks 1

Management of Specific Manifestations

Joint and Skin Manifestations

• For joint pain and cutaneous symptoms, oral prednisone at 1-2 mg/kg daily for two weeks may be beneficial 1, 2
• Colchicine (1 mg/day) may be considered for persistent purpura and pain, with treatment for at least six months 1
• NSAIDs should be avoided due to potential renal complications 1
• Acetaminophen (paracetamol) is recommended as a safer first-line analgesic option 1

Abdominal Symptoms

• Oral prednisone at 1-2 mg/kg daily for two weeks has been used to treat abdominal pain 2
• A meta-analysis found that corticosteroid use in children reduced the mean time to resolution of abdominal pain 2
• Severe gastrointestinal complications may require surgical intervention 3

Renal Disease Management

• For children with HSP nephritis and persistent proteinuria, treatment with ACE inhibitors or ARBs is recommended 1
• For children with persistent proteinuria >1 g/day per 1.73 m² after ACE inhibitor/ARB trial and GFR >50 ml/min per 1.73 m², a 6-month course of corticosteroid therapy is suggested 1
• For crescentic HSP with nephrotic syndrome and/or deteriorating kidney function, treatment with steroids and cyclophosphamide is recommended 1
• Prophylactic use of corticosteroids is not recommended to prevent HSP nephritis 1
• For severe nephritis, options include steroids combined with azathioprine, cyclosporine, tacrolimus, or mycophenolate mofetil/mycophenolic acid 1
• The same treatment approach is recommended for adults with HSP nephritis as in children 1

Severe and Refractory Cases

• Early aggressive therapy with high-dose steroids plus immunosuppressants is recommended for patients with severe renal involvement 2
• Methylprednisolone pulse therapy, immunosuppressive drugs (cyclophosphamide and azathioprine), plasma exchange, and polyclonal immunoglobulin therapy may be beneficial in life-threatening forms of the disease 3
• Dapsone has shown beneficial effects on cutaneous, gastrointestinal, and articular manifestations in adults, especially those with chronic forms 3

Monitoring and Prognosis

• Regular monitoring of renal function and urinalysis is essential, as renal involvement determines long-term prognosis 2, 3
• End-stage renal disease occurs in 1-5% of children with HSP 2
• Up to 20% of children with nephritis treated in specialized centers may require hemodialysis 3
• The renal prognosis appears to be worse in adults than in children 3
• Most cases resolve within a few weeks, but recurrences can occur 6

Common Pitfalls

• Failing to monitor for renal involvement, which is the main determinant of long-term prognosis 2, 3
• Using NSAIDs for pain management, which can worsen renal function 1
• Delaying diagnosis due to incomplete presentation (diagnosis may become obvious only when the characteristic rash emerges) 5
• Overlooking potential triggers such as infections, drugs, or underlying systemic diseases 3
• Assuming the disease is self-limited in all cases, when some patients (especially adults) may develop chronic nephropathy 3