Diagnosis and Management of Henoch-Schönlein Purpura

Diagnostic Approach

The American Academy of Pediatrics recommends diagnosing HSP clinically when palpable purpura is present plus at least one of the following: renal involvement, arthralgia/arthritis, or abdominal pain 1
The diagnosis requires palpable purpura plus at least one additional feature: diffuse abdominal pain, arthritis or arthralgia, renal involvement, or biopsy showing predominant IgA deposition 1
The clinical triad of hematuria, purpuric lesions, and ankle pain is diagnostic of HSP 1

Urinalysis with microscopy is essential to assess for glomerulonephritis, specifically looking 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 1
Basic metabolic panel including BUN and serum creatinine to assess renal function, with creatinine levels interpreted relative to age in pediatric patients 1, 2
Blood pressure measurement is mandatory as hypertension indicates more severe renal involvement 1

Pain management with acetaminophen is recommended as first-line analgesic, avoiding NSAIDs due to potential renal toxicity 1
Do NOT use NSAIDs in HSP patients due to risk of acute kidney injury, especially with pre-existing renal impairment 1

For children with HSP nephritis and persistent proteinuria, start ACE inhibitors or ARBs as first-line therapy 1, 3, 4
ACE inhibitors or ARBs are recommended for persistent proteinuria despite optimized supportive care 1, 3, 4
Target proteinuria to <1 g/day/1.73 m² rather than attempting complete normalization, which increases medication side effects without proven benefit 1
For persistent proteinuria >1 g/day per 1.73 m² after ACE inhibitor/ARB trial and GFR >50 ml/min per 1.73 m², add a 6-month course of corticosteroid therapy 1, 3, 4

Oral corticosteroids may be considered for severe gastrointestinal pain and gastrointestinal hemorrhage 1
Do NOT use corticosteroids prophylactically at HSP onset to prevent nephritis, as moderate quality evidence shows no benefit in preventing nephritis or reducing risk of severe persistent nephritis 1, 3, 4

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 1

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

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
Do NOT attempt to normalize proteinuria to <0.5 g/day/1.73 m², which increases side effects without proven benefit 1
Do NOT use corticosteroids prophylactically to prevent HSP nephritis, as this has no benefit based on strong evidence 1, 3, 4
Avoid NSAIDs including ketorolac due to nephrotoxicity risk 1

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, 3, 4