IgA Vasculitis - Henoch Schönlein Purpura

  • Diagnosis
  • Algorithms
  • Background
  • Lab Tests
  • References
  • Related Content

Indications for Testing

  • Palpable purpura in patient ≤20 years with other systemic symptoms

Criteria for Diagnosis

  • Diagnosis is primarily clinical
  • American College of Rheumatology Criteria (1990)
    • 2 of 4 must be present (sensitivity 87.1%, specificity 82.7%)
      • Palpable purpura
      • Age – ≤20 years
      • Bowel angina – defined as abdominal pain
      • Vascular wall granulocytes on biopsy seen in the arterioles and venules
  • EULAR criteria (2010)
    • Palpable purpura, not thrombocytopenic/petechiae (mandatory) and ≥one of the following
      • Diffuse abdominal pain
      • Histopathology – typical LCV with predominant IgA deposits or proliferative glomerulonephritis with predominant IgA deposits
      • Arthritis or arthralgias
      • Renal involvement
      • Proteinuria

        0.3 g/24 h

        OR

        >30 mmol/mg of urine albumin to creatinine ratio on a spot morning sample

        AND/OR

        Hematuria – red blood cell casts

        >5 red cells per high power field

        OR

        ≥2+ on dipstick

        OR

        Red blood cell casts in the urinary sediment

Laboratory Testing

  • Nonspecific testing – helpful in excluding other diagnoses or identifying organ dysfunction
    • CBC – normal platelet count rules out idiopathic thrombocytopenic purpura, thrombotic microangiopathies
    • Urinalysis – hematuria common
    • C-reactive protein (CRP)
    • BUN/creatinine – may be elevated from renal involvement or dehydration
    • Serum IgA – elevated in many patients

Histology

  • Granulocytes in small vessel (arterioles and venule walls) with IgA and C3 immune deposition
  • Glomerulonephritis of IgA vasculitis may be indistinguishable from IgA nephropathy or other glomerulonephritis

Differential Diagnosis

IgA vasculitis (formerly Henoch Schönlein purpura) is classified as a small-vessel vasculitis that predominantly affects the skin, gastrointestinal tract and can be associated with arthritis (Chapel Hill 2012). IgA vasculitis is the most common vasculitis of childhood.

Epidemiology

  • Incidence – 13-14/100,000 in U.S.
  • Age – typically diagnosed in children 3-10 years
    • Majority are diagnosed in children >5 years
  • Sex – M>F, 2:1

Pathophysiology

  • Systemic necrotizing small-vessel vasculitis characterized by tissue deposition of IgA containing immune complexes, most commonly in skin and kidney

Clinical Presentation

  • Typically a benign, self-limited disorder
    • A few cases cause chronic symptoms
    • Very small number of cases progress to end-stage renal failure
  • Classic clinical tetrad of symptoms
    • Rash – palpable purpura
      • Often concentrated on extensor surfaces of lower extremities
    • Polyarthralgia – most commonly in knees and ankles
      • Often edema also present
    • Abdominal pain – associated with nausea, emesis, diarrhea
      • Colicky quality
    • Renal disease – mild glomerulonephritis with microscopic hematuria, red cell casts, proteinuria
  • Other organ involvement
    • Neurologic (rare)
    • Pulmonary (rare)
      • Diffuse alveolar hemorrhage
    • May present as single organ vasculitis
  • Disease onset mostly occurs in the winter months, suggesting an infectious trigger
    • Frequently preceded by upper respiratory tract infection – ~50% of cases
    • Also associated with gastrointestinal infection
  • May be associated with other diseases or these diseases may be causal
    • Liver disease
    • IBD
    • Ankylosing spondylitis

Indications for Laboratory Testing

Tests generally appear in the order most useful for common clinical situations.
Click on number for test-specific information in the ARUP Laboratory Test Directory

CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

C-Reactive Protein 0050180
Method: Quantitative Immunoturbidimetry

Urinalysis, Complete 0020350
Method: Reflectance Spectrophotometry/Microscopy

Urea Nitrogen, Serum or Plasma 0020023
Method: Quantitative Spectrophotometry

Creatinine, Serum or Plasma 0020025
Method: Quantitative Enzymatic

Additional Tests Available

Sedimentation Rate, Westergren (ESR) 0040325
Method: Visual Identification

Comments

Evaluation for suspected vasculitis

Immunoglobulin A 0050340
Method: Quantitative Nephelometry

Comments

Screen for elevation

Guidelines

American Society for Clinical Pathology. Choosing Wisely - Five Things Physicians and Patients Should Question. An initiative of the ABIM Foundation. [Last revision Feb 2015; Accessed: Jan 2016]

Jennette J, Falk R, Bacon P, Basu N, Cid M, Ferrario F, Flores-Suarez L, Gross W, Guillevin L, Hagen E, Hoffman G, Jayne D, Kallenberg C, Lamprecht P, Langford C, Luqmani R, Mahr A, Matteson E, Merkel P, Ozen S, Pusey C, Rasmussen N, Rees A, Scott D, Specks U, Stone J, Takahashi K, Watts R. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum. 2013; 65(1): 1-11. PubMed

General References

Chen K, Carlson A. Clinical approach to cutaneous vasculitis. Am J Clin Dermatol. 2008; 9(2): 71-92. PubMed

Mills J, Michel B, Bloch D, Calabrese L, Hunder G, Arend W, Edworthy S, Fauci A, Leavitt R, Lie J. The American College of Rheumatology 1990 criteria for the classification of Henoch-Schönlein purpura Arthritis Rheum. 1990; 33(8): 1114-21. PubMed

Reamy B, Williams P, Lindsay T. Henoch-Schönlein purpura. Am Fam Physician. 2009; 80(7): 697-704. PubMed

Roberts P, Waller T, Brinker T, Riffe I, Sayre J, Bratton R. Henoch-Schönlein purpura: a review article. South Med J. 2007; 100(8): 821-4. PubMed

Ruperto N, Ozen S, Pistorio A, Dolezalova P, Brogan P, Cabral D, Cuttica R, Khubchandani R, Lovell D, O'Neil K, Quartier P, Ravelli A, Iusan S, Filocamo G, Magalhães C, Unsal E, Oliveira S, Bracaglia C, Bagga A, Stanevicha V, Manzoni S, Pratsidou P, Lepore L, Espada G, Kone-Paut I, Paut I, Zulian F, Barone P, Bircan Z, Maldonado M, Russo R, Vilca I, Tullus K, Cimaz R, Horneff G, Anton J, Garay S, Nielsen S, Barbano G, Martini A, Paediatric Rheumatology International Trials Organisation (PRINTO). EULAR/PRINTO/PRES criteria for Henoch-Schönlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part I: Overall methodology and clinical characterisation. Ann Rheum Dis. 2010; 69(5): 790-7. PubMed

Tizard E, Hamilton-Ayres M. Henoch Schonlein purpura. Arch Dis Child Educ Pract Ed. 2008; 93(1): 1-8. PubMed

Yang Y, Yu H, Chiang B. The diagnosis and classification of Henoch-Schönlein purpura: an updated review. Autoimmun Rev. 2014; 13(4-5): 355-8. PubMed

Medical Reviewers

Last Update: December 2015