What is the approach to diagnosis and management of Henoch-Schonlein purpura (HSP) in a pediatric patient, likely between 3-10 years old, presenting with suspected HSP?

Diagnosis and Management of Pediatric Henoch-Schönlein Purpura

Diagnose HSP clinically when palpable purpura is present plus at least one of the following: renal involvement (hematuria/proteinuria), arthralgia/arthritis, or abdominal pain—no biopsy is required for typical presentations. 1

Diagnostic Approach

Clinical Diagnosis Criteria

• Make the diagnosis when palpable purpura (non-thrombocytopenic) is present PLUS at least one additional feature: diffuse abdominal pain, arthritis or arthralgia, renal involvement (hematuria and/or proteinuria), or biopsy showing predominant IgA deposition. 1, 2
• The classic triad of hematuria, purpuric lesions, and ankle pain is diagnostic of HSP. 1
• Approximately 90% of cases occur in children between 2 and 10 years of age, with peak incidence at 4 to 7 years. 2

Mandatory Initial Laboratory Evaluation

• Urinalysis with microscopy is essential to assess for glomerulonephritis—specifically look for proteinuria, red blood cell casts, and dysmorphic red blood cells indicating glomerular involvement. 1
• Complete blood count with platelets to confirm non-thrombocytopenic purpura and rule out other causes (ITP, leukemia, meningococcemia). 1
• Basic metabolic panel including BUN and serum creatinine to assess renal function, with creatinine levels interpreted relative to age in pediatric patients. 1, 3
• Blood pressure measurement is mandatory as hypertension indicates more severe renal involvement. 1, 3

When to Consider Biopsy

• Perform renal biopsy if the patient presents with decreased renal function, severe nephrotic syndrome, or nephritic syndrome at initial presentation. 3
• Intestinal biopsies (if endoscopy performed for severe GI symptoms) show IgA deposition and leukocytoclastic vasculitis in submucosal vessels. 4

Management Strategy

General Supportive Care

• Use acetaminophen as first-line analgesic for pain management. 1
• Do NOT use NSAIDs (including ibuprofen, ketorolac) in HSP patients due to risk of acute kidney injury, especially with pre-existing renal impairment. 1
• Most cases are self-limited with an average disease duration of 4 weeks. 2

Management of Gastrointestinal Symptoms

• Oral corticosteroids (prednisone 1-2 mg/kg daily for two weeks) may be considered for severe gastrointestinal pain and gastrointestinal hemorrhage. 1, 2
• Periumbilical and epigastric pain typically worsens with meals due to bowel angina. 4
• Ultrasound is recommended as the first diagnostic test for suspected intussusception (the most common surgical complication), which is usually ileo-ileo or ileo-colic. 4
• Endoscopy may show gastritis, duodenitis, ulceration, and purpura, with the second portion of the duodenum characteristically involved more than the bulb. 4

Critical Pitfall: Prophylactic Corticosteroids

• Do NOT use corticosteroids prophylactically at HSP onset to prevent nephritis—moderate quality evidence shows no benefit in preventing nephritis or reducing risk of severe persistent nephritis. 1, 3, 2
• Early steroid treatment does not reduce the incidence and severity of nephropathy in children with HSP. 2

Management of Renal Involvement

Initial Approach to HSP Nephritis

• For children with HSP nephritis and persistent proteinuria, start ACE inhibitors or ARBs as first-line therapy. 1, 2
• ACE inhibitors or ARBs are recommended for persistent proteinuria despite optimized supportive care. 1
• Target proteinuria to <1 g/day/1.73 m² rather than attempting complete normalization, which increases medication side effects without proven benefit. 1, 3

When to Escalate to Corticosteroids

• For persistent proteinuria >1 g/day per 1.73 m² after ACE inhibitor/ARB trial (8-12 weeks) and GFR >50 ml/min per 1.73 m², add a 6-month course of corticosteroid therapy. 1, 3
• Do NOT start corticosteroids too early for mild proteinuria without adequate trial of ACE inhibitor/ARB therapy, as this increases side effects without proven benefit. 1

Crescentic HSP Nephritis (Severe Disease)

• Administer high-dose intravenous methylprednisolone immediately for crescentic HSP with nephrotic syndrome and/or deteriorating kidney function. 3
• Add cyclophosphamide as the only immunosuppressive agent with RCT evidence for crescentic HSP nephritis in children. 3
• Do NOT delay renal biopsy in patients with decreased renal function at presentation, as crescentic disease requires immediate aggressive therapy. 3

Management of Joint and Cutaneous Symptoms

• For joint pain and cutaneous symptoms, oral prednisone at 1-2 mg/kg daily for two weeks may be beneficial. 1
• Colchicine may be considered for persistent purpura and pain, with treatment for at least six months—colchicine yielded favorable response in 11 of 12 relapsing patients who did not respond to ibuprofen or steroids. 1, 5

Dietary Considerations

• A low-antigen-content diet may improve symptoms and laboratory abnormalities when strictly followed for 4-8 weeks, and can be considered as supportive treatment in all symptomatic patients. 1
• The low-antigen-content diet can be used in conjunction with other treatments, such as colchicine, for chronic or persistent symptoms. 1

Follow-Up and Monitoring

Duration and Frequency

• Follow-up for children presenting with HSP should be for at least 6 months and should include regular urine testing for proteinuria and hematuria and blood pressure measurement. 6, 7
• A normal urinalysis on day 7 has a 97% (confidence interval 90 to 99%) negative predictive value in predicting a normal renal outcome. 7
• Prioritize intensive monitoring for patients with abnormal urine findings on day 7, as they are at higher risk of developing nephritis. 7

Risk Stratification

• Older patients (especially adolescents) are at higher risk of severe renal involvement—renal referral patients average 12.3 years vs. 6.0 years for those with normal outcomes. 3, 7
• Adolescents with HSP have worse outcomes than younger children, with higher rates of severe renal involvement, persistent nephritis, and progression to end-stage renal disease (1-5% overall). 3
• Frequencies of renal involvement and biopsy-proven nephritis are higher in patients with severe GI involvement. 5

Special Population: Pregnancy

• Women with a history of HSP during childhood are at increased risk of complications (such as proteinuria and hypertension) during pregnancy and should be monitored closely. 6

Long-Term Prognosis

• Most cases of HSP have an excellent outcome, with renal involvement being the most important prognostic factor in determining morbidity and mortality. 2
• Long-term complications are rare and include persistent hypertension and end-stage kidney disease. 2
• Disease recurs at least once in approximately 16.4% of patients. 5
• Adult HSP nephritis should be treated using the same approach as children, though adults have worse prognosis and higher risk of progression to end-stage renal disease. 1