Updated: 3/31/2018

Small Vessel Vasculitides with Immune Complexes

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Snapshot
  • A 5-year-old boy presents to the emergency room for abdominal pain and rash on his legs. He also reports having intermittent joint pains. A few weeks ago, he had an upper respiratory infection. On physical exam, he has nontender palpable purpura on his buttocks and lower extremities. His abdomen is mildly tender. Urine studies show proteinuria and hematuria. (Henoch-Schonlein purpura/IgA vasculitis)
Introduction
  • Clinical definition
    • vasculitis caused by immune complex deposition
  • Pathogenesis
    • circulating antigens induce antibody formation
      • the antibodies then bind to antigens, creating immune complexes
    • the immune complexes then deposit in small vessels, activating complement and causing a vasculitis
  • General clinical features
    • palpable dark-red or purple purpura
    • may itch, burn, or be nontender
    • may ulcerate
  • Studies
    • most cases are diagnosed clinically, but a biopsy may be needed
    • direct immunofluorescence
      • deposition of C3, IgM, IgA, and/or IgG
Cryoglobulinemic Vasculitis
  • Clinical definition
    • small-vessel vasculitis caused by mixed cryoglobulins affecting the skin, peripheral nervous system, and kidneys
      • associated with hepatitis C virus (HCV) infection
      • occurs in adults
  • Presentation
    • peripheral neuropathy
    • skin involvement
      • palpable purpura
      • ulcerations
      • livedo reticularis
    • joint pain
    • renal involvement
      • membranoproliferative glomerulonephritis
    • no gastrointestinal symptoms (in contrast to Henoch-Schonlein purpura)
  • Studies
    • cryoglobulins isolated from the serum
    • urine studies
      • proteinuria
      • hematuria
  • Treatment
    • treat underlying HCV infection
    • corticosteroids
Henoch-Schonlein purpura (IgA Vasculitis)
  • Clinical definition
    • IgA-mediated small vessel vasculitis that often follows an upper respiratory infection  
      • especially with group A streptococcus or parvovirus B19
      • occurs in children
  • Presentation
    • triad of 
      • nontender palpable purpura
        • on buttocks and lower extremities
        • may ulcerate
      • arthralgias
      • colicky abdominal pain
    • constitutional symptoms
    • hematuria
  • Studies
    • urine studies
      • proteinuria
      • hematuria
    • direct immunofluorescence
      • IgA deposition in small vessels on direct immunofluorescence
    • histology
      • IgA deposition in small vessels on staining
      • leukocytoclasis
  • Treatment
    • typically resolves spontaneously over time
    • angiotensin-converting enzyme (ACE) inhibitor
      • indication
        • for persistent proteinuria, which may result in end-stage renal disease or glomerulonephritis
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Questions (5)

(M1.CV.17.4732) An 8-year-old girl is brought to the physician by her parents due to a new rash on her feet and legs. Her parents noticed the rash one day ago, and the child has also been complaining of joint pain and abdominal pain. She has no chronic medical conditions and has not been traveling or spending time outdoors recently. She had an upper respiratory infection seven days ago which resolved on its own. On exam, her vital signs are normal, and she is generally well-appearing. Her joints have full range of motion with no evidence of trauma. Her abdomen is soft and non-distended and is mildly tender to deep palpation diffusely. The patient has the notable findings in Figure A which are non-blanchable. The results of a complete blood count are within normal limits. Her urinalysis shows > 20 RBCs.

What is most likely responsible for this patient’s dermatologic findings?
Tested Concept

QID: 108620
FIGURES:
1

Thrombocytopenia

22%

(47/215)

2

Mast cell degranulation

2%

(5/215)

3

Bacterial infection

10%

(21/215)

4

IgA immune complex deposition

63%

(136/215)

5

Venous stasis

0%

(0/215)

M 2 C

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(M1.CV.15.74) A 7-year-old boy is brought to the emergency department by his mother. He had a recent cold, and is now complaining of colicky abdominal pain. However, his mother became very concerned and brought him to the emergency department when she noted the rash shown in Figure A. On further review, the boy says that his elbows and knees have been hurting him. A complete blood count is within normal limits. What type of pathological process underlies his disorder? Tested Concept

QID: 106683
FIGURES:
1

Vasculitis with c-ANCA

16%

(24/154)

2

IgA vasculitis

70%

(108/154)

3

Telescoping of bowel segment

2%

(3/154)

4

Inflammatory bowel disease

2%

(3/154)

5

Anti-platelet antibody

8%

(13/154)

M 2 D

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(M1.CV.13.68) A 3-year-old female presents to the emergency department with colicky abdominal pain, polyarthralgias and the palpable rash shown in Figure A. You are concerned that complications of her disease may include: Tested Concept

QID: 100584
FIGURES:
1

Septic shock

0%

(0/16)

2

Glomerulonephritis

62%

(10/16)

3

Deafness

6%

(1/16)

4

Rheumatic fever

25%

(4/16)

5

Aortic regurgitation

6%

(1/16)

M 2 E

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(M1.CV.13.47) An 3-year-old male complains of abdominal pain following an upper respiratory infection. On physical examination, you note the dermatologic abnormality shown in Figure A. Which of the following is most likely involved in the pathogenesis of this patient's disease? Tested Concept

QID: 100468
FIGURES:
1

IgA

62%

(80/129)

2

IgE

11%

(14/129)

3

IgG

12%

(16/129)

4

C5a

6%

(8/129)

5

C3b

9%

(11/129)

M 1 D

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(M1.CV.12.2) An 8-year-old boy presents to your office with joint pain, hematuria, and blood in the stool following an episode of pharyngitis 2 weeks ago. Examination reveals palpable red lesions on the lower extremities as seen in Figure A. This patient's disease is most similar to which of the following diseases? Tested Concept

QID: 100956
FIGURES:
1

Idiopathic thrombocytopenic purpura

12%

(2/17)

2

Systemic lupus erythematosus

12%

(2/17)

3

Buerger's disease (thromboangiitis obliterans)

12%

(2/17)

4

Berger's disease (IgA nephropathy)

65%

(11/17)

5

Osler-Weber-Rendu syndrome

0%

(0/17)

M 1 E

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Evidence (5)
Topic COMMENTS (7)
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