IgA vasculitis: SAQ

This boy has the classic tetrad of IgA vasculitis, and the framework that organises the answer is the EULAR/PRINTO/PRES classification, the selective corticosteroid decision, and the renal monitoring schedule that is the safety-net for the disease. [3]

Question 1 (10 marks)

Discuss the diagnosis and classification of this condition, the acute management including the corticosteroid decision, and the renal monitoring schedule. [1]

A full-mark answer reproduces the classification criteria, the corticosteroid evidence, and the monitoring schedule. [3]

Diagnosis and classification (3 marks). This is IgA vasculitis (Henoch-Schonlein purpura), the commonest childhood small-vessel vasculitis. The EULAR/PRINTO/PRES Ankara 2008 criteria require the mandatory palpable purpura, defined as the raised non-thrombocytopenic rash on the dependent areas, plus at least one of diffuse abdominal pain, IgA deposition on biopsy, arthritis or arthralgia, or renal involvement. This boy meets all four: the palpable purpura, the arthritis, the abdominal pain, and the renal involvement (microscopic haematuria with trace protein). The normal platelet count and coagulation exclude the idiopathic thrombocytopenic purpura and the coagulopathy. The criteria carry a sensitivity of 100 percent and a specificity of 87 percent against the other childhood vasculitides, and the diagnosis is clinical in the classic case. [1]

Acute management and the corticosteroid decision (4 marks). The management is largely supportive, with the corticosteroid reserved for the specific severe indications. The supportive care is the rest, the hydration, and the analgesia with the paracetamol at 15 milligrams per kilogram per dose, with the non-steroidal anti-inflammatory drugs used only when the renal function is normal. The corticosteroid indications are the severe abdominal pain, the severe arthritis unresponsive to the simple analgesia, the severe scrotal involvement, and the severe renal disease, at prednisolone 1 to 2 milligrams per kilogram per day. The critical evidence is that the prednisone does not reliably prevent the nephropathy: the randomised trial of Ronkainen found that the early prednisone relieved the severe abdominal and joint pain but did not prevent the renal involvement, and the Cochrane review of Chartapisak confirmed that the routine corticosteroid for the renal prevention is not supported. This boy has the colicky abdominal pain; if it is severe and unresponsive to the paracetamol, with the intussusception excluded, he receives the prednisolone for the symptomatic relief. [2][5]

Renal monitoring schedule (3 marks). Every child with IgA vasculitis, regardless of the corticosteroid use, is monitored by the blood pressure and the urinalysis weekly for the first 4 to 6 weeks, then monthly for 6 months, because the renal involvement can declare as late as six months after the onset, in a child who looks completely well. The family is given the clear safety-net to return for the reduced urine, the swelling, the headache, and the dark or the bloody urine. The significant renal involvement, defined as the nephrotic syndrome, the nephritic syndrome, the persistent proteinuria, or the declining renal function, triggers the nephrology referral and the consideration of the renal biopsy. The monitoring is the single most important safety-net, because the renal involvement determines the long-term outcome. [3][6]

Question 2 (10 marks)

Discuss how your management would change if he presented instead with a nephrotic-range proteinuria and a blood pressure of 120 over 80, or with severe worsening abdominal pain, a palpable mass, and bile-stained vomiting. [7]

A full-mark answer reproduces the renal biopsy and immunosuppression pathway, and the intussusception and surgical pathway. [3]

The nephrotic-range proteinuria with hypertension (5 marks). The heavy proteinuria with the hypertension is the significant renal involvement, the nephritic-nephrotic overlap, and it changes the management from the supportive care to the active nephritis pathway. The renal biopsy is performed to grade the injury by the International Study of Kidney Disease in Children classification, with the crescents and the sclerosis marking the severe disease. The management includes the angiotensin-converting-enzyme inhibitor for the proteinuria and the blood pressure, because it reduces the intraglomerular pressure and the protein leak. The immunosuppression is guided by the nephrology team, and may include the high-dose corticosteroid with or without the cyclophosphamide, the azathioprine, the mycophenolate mofetil, or the rituximab, though the evidence base is less robust than for the corticosteroid. The child is followed by the paediatric nephrology for the long term, because the significant renal involvement carries the risk of the chronic kidney disease and the end-stage renal failure in around 1 to 3 per cent of all cases, concentrated in this group. [4][6]

The severe worsening abdominal pain with the mass and the bile-stained vomiting (4 marks). This is the intussusception until proven otherwise, and it is a surgical emergency. The first-line investigation is the abdominal ultrasound, which shows the target sign and the length of the involved segment. The intussusception in IgA vasculitis is often ileo-ileal, unlike the classic ileo-caecal intussusception of the infant, and the ileo-ileal location means that the air or the barium enema often fails and the surgical reduction may be needed. The surgical review is sought immediately, and the corticosteroid is given for the concurrent vasculitic inflammation once the surgical plan is set. The other gastrointestinal complications to name are the occult or the frank bleeding and the rare perforation. [3][7]

Synthesis (1 mark). The fellow who holds the classification criteria, the selective corticosteroid decision, the renal monitoring schedule, the renal biopsy pathway, and the intussusception pathway has the framework that organises the whole management of IgA vasculitis. [3]