Small Vessel Vasculitis for PA
Small Vessel Vasculitis for the Physician Assistant Licensing Exam
Overview of Small Vessel Vasculitis
Small vessel vasculitis (SVV) involves inflammation of the smallest blood vessels, including capillaries, venules, and arterioles. This inflammation can lead to multi-organ involvement, with varying symptoms based on the affected organs and underlying disease type.
Classification of Small Vessel Vasculitis
- ANCA-Associated Vasculitides (AAV): Defined by antineutrophil cytoplasmic antibodies (ANCA) that cause vascular inflammation.
- Granulomatosis with Polyangiitis (GPA): Formerly Wegener’s granulomatosis, GPA often affects the respiratory tract and kidneys. PR3-ANCA (c-ANCA) is commonly associated.
- Microscopic Polyangiitis (MPA): Primarily involves the kidneys and lungs, often without granulomas, and is usually MPO-ANCA (p-ANCA) positive.
- Eosinophilic Granulomatosis with Polyangiitis (EGPA): Also known as Churg-Strauss syndrome, EGPA is marked by asthma, eosinophilia, and p-ANCA.
- Immune Complex–Mediated Vasculitides:
- IgA Vasculitis (Henoch-Schönlein Purpura): Predominantly affects children and presents with palpable purpura, abdominal pain, and arthritis due to IgA deposits.
- Cryoglobulinemic Vasculitis: Associated with hepatitis C and presents with palpable purpura, arthralgia, and renal disease due to cryoglobulin deposits.
Clinical Presentation
- Common Features: Fever, malaise, weight loss, and palpable purpura on the lower extremities are frequent in SVV.
- Granulomatosis with Polyangiitis (GPA):
- Respiratory Tract: Chronic sinusitis, nasal ulcers.
- Lungs: Nodules, hemoptysis.
- Kidneys: Rapidly progressive glomerulonephritis (RPGN).
- Microscopic Polyangiitis (MPA):
- Kidneys: RPGN with hematuria and proteinuria.
- Lungs: Alveolar hemorrhage with hemoptysis.
- Eosinophilic Granulomatosis with Polyangiitis (EGPA):
- Lungs: Asthma, transient pulmonary infiltrates.
- Nervous System: Mononeuritis multiplex.
- Skin: Purpura and nodules.
- IgA Vasculitis:
- Skin: Purpura, often on legs.
- GI Tract: Abdominal pain, possible GI bleeding.
- Kidneys: Hematuria, proteinuria.
- Cryoglobulinemic Vasculitis:
- Skin: Purpura, often in extremities.
- Kidneys: Membranoproliferative glomerulonephritis.
- Neurologic: Peripheral neuropathy.
Key Points
- Types: ANCA-associated vasculitides (GPA, MPA, EGPA) and immune complex–mediated vasculitides (IgA vasculitis, cryoglobulinemic vasculitis).
- Presentation: Common symptoms include palpable purpura and multi-organ involvement.
- Diagnosis: ANCA testing, cryoglobulin levels, and biopsy findings help confirm SVV.
- Treatment:
- Glucocorticoids for inflammation.
- Cyclophosphamide or Rituximab in severe AAV cases.