Henoch Schonlein Purpura

Transcription

1 CHILDREN S SERVICES Henoch Schonlein Purpura Definition A vasculitic syndrome of small vessels classically characterised by a purpuric rash, abdominal pain, arthritis, and nephritis. Platelet count and clotting screen are normal. Vasculitis is caused by deposition of IgA-containing immune complexes with subsequent activation of complement. As per the American College of Rheumatology 1990 criteria for the classification of Henoch Schonlein purpura two out of following four criteria are needed for diagnosis: 1. Age < 20yrs 2. Palpable purpura 3. Bowel angina - diffuse abdominal pain or bowel ischemia usually with bloody diarrhoea 4. Biopsy showing granulocytes in the wall of arterioles and venules The classic tetrad of purpuric rash, arthralgia, abdominal pain and nephritis is pathognomonic of HSP Epidemiology HSP is the most common form of systemic vasculitis in children. 75% of cases are aged 2-11, and the disease tends to be milder in age <2. The incidence is higher in males than females ( :1) and greater in spring and autumn. It is thought that HSP pathogenesis is related to an abnormal response to antigenic stimulants eg antibiotics, infections (e.g streptococcus, mycoplasma, adenovirus, EBV), and post vaccination. Please see the Trust antibiotic guidelines Clinical Features Children often present with a triad of purpura, abdominal pain, and arthritis. Skin Manifestations: 50% at onset, 100% during course. Purpura on extensor surfaces of lower limbs and buttocks, sometimes upper limbs, trunk and face. May evolve from erythematous maculopapules to red/purple petechiae and/or purpura to brownish patches, then fade. May give polymorphic appearance as new crops appear. May be pruritic. Subcutaneous oedema of limbs and scrotum can occur in up to 50% during course of the disease. This is angioedema and not related to renal disease. 1

2 Rheumatological Manifestations: 25% at onset, 60-85% during course. Most commonly affects ankles and knees. Tends to be transient, but recurs in active disease. Unlikely to cause permanent deformity. Gastrointestinal Manifestations: 30% at onset, 85% during course. Colicky abdominal pain, with vomiting, tends to occur after the onset of rash and joint pain. Frank, or occult blood, may occur in stool with haematemesis. Intussusception may occur in 2-3%. Bowel infarction, perforation or massive GI bleed are unusual complications. Renal Manifestations: 10-50% during course. Renal problems usually develop within 3 months of onset of rash, but may occasionally precede rash. Renal involvement is more likely with GI symptoms, persistent rash for 2-3 months, or episodic purpura. 1% will have persistent nephropathy. <1% will have end stage renal failure. Spectrum of renal involvement varies: Haematuria Microscopic with proteinuria <2g/day, preserved renal function, does not evolve to end stage renal disease (ESRD). Nephritic Syndrome Haematuria with hypertension decreased renal function, proteinuria and oliguria. 15% develop ESRD. Nephrotic Syndrome Urinary protein excretion >40mg/m2/hr (+++) 50% with both nephritic and nephrotic syndromes develop ESRD within 10 years of onset. Indications for renal biopsy Renal impairment, hypertension, significant hypo-albuminaemia and heavy proteinuria (plasma albumin <25gm/l) Neurological Manifestations, such as altered mental state, seizures and focal deficits are very rare and, again, other causes should be considered Assessment Meningococcal septicaemia must be excluded 2

3 History: Length of illness, recent URTI, abdominal pain, joint pain haematuria Examination: Temperature, blood pressure, palpable purpura (mainly extensor surfaces),abdominal tenderness, joint tenderness and swelling (mainly knees and ankles) Investigations: FBC,U&E, CRP Clotting screen ASOT, Throat swab Urine dipstick and MC&S if dipstick +ve BC only if child unwell Renal function should be checked at the onset of each exacerbation of symptoms and repeated if the symptoms and haematuria persist for more than a few days. Criteria for admission Severe joint pain or swelling restricting movement - admit for analgesia, physiotherapy and early mobilisation. Severe abdominal pain- admit for analgesia and investigation. Arrange urgent ultrasound of abdomen. Do not refer to surgeons until discussed with Paediatric Consultant. Renal involvement with haematuria and proteinuria. Oliguria, hypertension or decreased renal function indicates possibility of a more complicated course Treatment NSAIDs: for joint and abdominal pain if platelet count normal Steroids: Use of steroid is still controversial. Steroid does hasten the resolution of the self limiting pain and has been suggested to reduce hospital stay. Hence it might be indicated in moderate to severe pain Proven usefulness in moderate to severe GI haemorrhage Likely to be useful in scrotal / testicular involvement but more evidence awaited Their usefulness in preventing future renal involvement continues to be controversial with conflicting results. Present evidence does not support routine use of steroid for prevention of nephropathy 3

4 Steroid in various strength and combination has been found useful in the treatment of HSP nephropathy but this is usually initiated at tertiary renal centres. NOTE:.Use of steroid and its duration should always be discussed with the attending consultant Current evidence for/against use of steroid for preventing subsequent nephropathy is attached at the end A large multi centre randomised control trial on use of steroids in HSP has been recently concluded at Bristol and awaiting publication Follow up arrangements Every child will need to be followed up for a minimum of 6 months. Individual cases should be discussed with the attending consultant During each visit clinical symptoms, BP and urinalysis must be monitored. Renal function should be measured during each exacerbation of symptoms. Children with haematuria alone will need to be followed up until 1 year free of haematuria. Children with haematuria and proteinuria needs lifelong follow up by a nephrologist. Parents should be given information leaflet explaining to seek urgent medical attention for; sudden onset of severe abdominal pain, distension, periorbital edema, haematemesis and melaena There is a parent information leaflet available on the intranet. References: 1. Mills JA et al The American College of Rheumatology 1990 criteria for the classification of Henoch Schonlein purpura Arthritis Rheum 1990;33: Rosenblum ND et al Steroids effect on the course of abdominal pain in HSP Pediatrics 1987 Vol 79 No Buchanec J et al Incidence of renal complication in Schonlein-Henoch purpura syndrome in dependence of early administration of steroids Int J nephrol 1988;20: Mollica F et al Effectiveness of early prednisolone treatment in preventing the development of nephropathy in anaphylactoid purpura Eur J Pediatr 1992;151: Saulsbury FT Corticosteroid therapy does not prevent nephritis in HSP Pediatr Nephrol 1993;7:

5 6. Renal involvement in Henoch Schonlein purpura : A multivariate analysis of prognostic factors Kaku Y Kidney International Vol 53(1998) Henoch Schonlein purpura Tizard EJ Arch Dis Child 1999,80 : ( April) 8. Huber A et al A randomised placebo-controlled trial of prednisone in early Henoch Schonlein purpura BMC Medicine 2004, 2:7 Author: Dr Rajiv Sinha SpR Paediatric Modified from previous protocol by Dr E. Dawson Staff Grade A&E Date: December 2006 Reviewed and updated: August 2013 Dr Erin Dawson, Associate Specialist Emergency Paediatrics Next review: August 2015 Ratified by Dr. D. Haddad on behalf of the Children s Services Directorate Clinical Governance Committee on 18 th May