Henoch-Schonlein purpura



Background

  • Any child with a rash, abdominal pain and arthritis/arthralgia should have HSP considered as a diagnosis.
  • IgA complex mediated small vessel vasculitis
  • Any age (majority from 2-8 years)
  • M:F=2:1

Clinical assessment

  • Airway, Breathing, Circulation – HR, BP, CRT, Temperature
  • Full CVS, chest and abdominal examination
  • Examination of all joints for pain and/or swelling
  • Urine dipstick

Clinical manifestations

Onset may be acute or (50%) chronic have malaise and low grade fever

Skin

  • Always present but extremely variable presentations
  • Classically on lower extremities and buttocks on the extensor surfaces, but can affect upper extremities, face and trunk.
  • Classic lesions are reddish/purple in colour, slightly raised and palpable (erythematous maculopapules). They initially blanch on pressure but can become purpuric or petechial
  • Purpuric areas change from red to purple to fading
  • They may appear in crops and a variety may occur at any time
  • Various patterns of erythema multiforme and erythema nodosum may rarely occur

Arthritis

  • Approximately 2/3 of affected children
  • Large joints, especially knees and ankles are most commonly affected
  • It is transient and non-migratory
  • Children present with swollen, tender, painful joints
  • Joint effusions are serous not haemorrhagic
  • Arthritis generally resolves in a few days with no residual deformity or joint damage.
  • It may recur in periods of active disease

GI

  • Approximately 2/3 of children affected
  • GI symptoms occur before the rash in 25% of children.
  • Colicky abdominal pain (98%), with or without vomiting.
  • Gut wall oedema & haemorrhage may result in gross or occult blood per rectum
  • Upper GI haemorrhage (5%) and intussusception or obstruction are rare

Renal

  • 40-50% of children in the acute phase, with some degree of renal insufficiency in 5% and chronic renal failure in up to 1.5%.
  • Casts or proteinuria may occur in the first few weeks or can appear later after the other manifestations have settled.
  • 20-30% of children may have gross haematuria.
  • Occasionally moderate hypertension, oliguria and more rarely, hypertensive encephalopathy, may occur.
  • Those that develop chronic renal disease do so within a few years of the acute phase of HSP
  • Signs of renal involvement may take up to 3 months to develop. If they are not there by 3/12 they are unlikely to develop.
  • Renal involvement may be present in patients with or without haematuria. it is more likely in children with haematuria or a persistent rash.

CNS

  • Rare but potentially serious complications such as seizures, paresis and coma may occur.

Other

  • Hepatosplenomegaly and lymphadenopathy during the acute phase
  • Testicular swelling, pain (orchitis or necrosis) and haemorrhage
  • Intramuscular haemorrhage
  • Rheumatoid like nodules
  • Cardiac involvement
  • Eye involvement

Diagnosis

Any child with a rash, abdominal pain and arthritis/arthralgia should have HSP considered.

Differential diagnoses

  • (Excluded from history and examination findings)
  • Meningococcal septicaemia
  • Thrombocytopenia
  • Viral exanthem
  • Septic arthritis
  • Rarely systemic vasculitides – Wegeners, SLE, hypersensitivity vasculitis, polyarteritis nodosa

Investigations

There are no diagnostic tests

  • Urine microscopy – RBC, WBC, casts, or albumin
  • Weight and height
  • BP
  • In those with proteinuria/macroscopic haematuria:
    • FBC (eosinophilia, normal platelet count)
    • Clotting (normal)
    • U&E, creatinine, bone profile
    • Early Morning Urine protein/creatinine ratio
  • Consider: Stool sample for microscopy or occult blood if infective cause for PR bleeding is a possibility.

Additional investigations:

  • ASOT titre/Anti DNA’ase B titres and throat swab to exclude streptococcal infection
  • Complement C3, 4
  • Autoimmune profile
  • pANCA, cANCA
  • Renal USS

Management

There is no specific therapy

  • Supportive: hydration, nutrition, electrolyte balance.
  • If allergens are proven then they should be avoided or treated e.g. streptococcal infection.
  • Simple analgesia. Use NSAIDs with caution
  • With severe abdominal pain, arthritis, pulmonary haemorrhage consider prednisolone
  • With severe skin manifestations discuss the use of colchicine or dapsone

Hypertensive = BP > 97th centile on one reading, or > 90th centile on 3 readings.

Prognosis

  • Microscopic haematuria without proteinuria generally has a benign course.
  • Isolated microscopic haematuria/mild proteinuria have a good prognosis, with often only mild histological changes.
  • < 5% develop CRF, <5% ESRD in 10-25 years.
  • Increasing proteinuria or the development of nephrotic syndrome or renal insufficiency are indicators of severe disease.
  • Of those that develop acute nephritic/nephrotic syndrome, 20% progress to ESRD, 44-50% develop hypertension, abnormal renal function or CRF.
  • Chronic renal disease may occur in approx 1% of patients.
  • 25% of children with renal disease may have persistence of urine sediment for several years.
  • Haematuria at the onset of the disease or renal manifestations within the first 3 months after the onset of disease were significantly more common in one group of children with renal sequelae at one year follow-up.

Content by Dr Íomhar O' Sullivan 09/06/2005. Reviewed 09/010/2006. Last review Dr. IOS 19/01/15.