IgA Vasculitis (Henoch-Schonlein purpura)

Question 1

Define Henoch-Scholein pupura.

Answer 1

Henoch-Schonlein purpura (HSP) is the most common vasculitis of childhood and affects the small vessels. HSP is characterised by the classic tetrad of rash, abdominal pain, arthritis/arthralgia, and glomerulonephritis.

Question 2

Explain the aetiology/risk factors for HSP.

Answer 2

HSP is a small-vessel leukocytoclastic vasculitis characterised by the tissue deposition of IgA-containing immune complexes within affected organs. Skin biopsies of lesions show neutrophils and monocytes as the predominant cell types. Fluorescence microscopy shows IgA, C3, and fibrin deposition within the small vessels. In the mesangial region of the kidney, the prominent feature by fluorescence microscopy is the deposition of IgA, C3, fibrin, and occasionally IgG. The pathogenesis of this disease is similar to that of IgA nephropathy. The vasculitis may also occur in other organs, including the GI tract.

Question 3

Summarise the epidemiology of HSP.

Answer 3

HSP is mainly a disease of children that occurs predominantly between the ages of 3 and 15 years. About 50% of all cases occur at or before the age of 5 years. M:F 2:1 The true prevalence may be underestimated because cases are often not reported. HSP can follow a URTI, and as a result it mainly occurs in the autumn, winter, and spring.

Question 4

What are the presenting signs and symptoms of HSP.

Answer 4

Purpura or petechiae (mandatory) with lower limb predominance and at least 1 of the 4 following criteria:

• Abdominal pain
• Histopathology
• Arthritis or arthralgia
• Renal involvement

Question 5

What are appropriate investigations for HSP?

Answer 5

Urine: assess for renal involvement; Microscopy; RBC and culture, 24-hour collection; protein and creatinine clearance

Bloods: FBC, U&E, serum creatinine, ESR/CRP, GFR There is no other specific test for HSP.

Question 6

What is the management for HSP?

Answer 6

Most cases of HSP resolve spontaneously (usually within 4 weeks) and the primary goal is to provide symptomatic treatment. Complete recovery occurs in 94% of children and 89% of adults. One third of patients may have a recurrence within 4 months, but the subsequent episode is generally milder; recurrences are more common in patients with nephritis.

Question 7

How are the symptoms for HSP treated?

Answer 7

• Abdo pain – paracetamol
• Joint pain – Ibuprofen
• Scrotal involvement or severe oedema or severe abdominal pain (based on patient’s history, physical examination findings, and clinical judgment) are managed with oral prednisolone
• Nephrotic-range proteinuria and/or those with declining renal function, and intravenous corticosteroids (pulse dosing) are recommended
• Renal impairment with rapidly progressive nephritis generally requires a combination of corticosteroids, immunosuppressants, and plasmapheresis
• Renal transplant may be required in patients who progress to end-stage renal disease

Question 8

What are complications associated with HSP?

Answer 8

Renal impairment but usually none

Question 9

What is the prognosis of HSP?

Answer 9

Usually excellent