Vasculitides

This article deals with the vasculitides (singular vasculitis).

Overview

Most common

• Polyarteritis nodosa (PAN).
• Microscopic polyangiitis.
• Wegener's granulomatosis.
• Predominantly cutaneous vasculitis.
• Giant cell arteritis (GCA).

Grouping by size

Small vessel vasculitides

• Predominantly cutaneous vasculitis.
• Henoch-Schoenlein purpura.
• Essential cryoglobulinemic vasculitis.
• ANCA-associated:
  • Wegener's granulomatosis (c-ANCA > p-ANCA).
  • Churg-Strauss syndrome (50% ANCA +ve).
  • Microscopic polyangiitis (usually p-ANCA).

Notes:

• ANCA = anti-neutrophil cytoplasmic antibodies.

Large vessel vasculitides

• Giant cell arteritis (AKA temporal arteritis).
• Takayasu's arteritis.

Giant cell arteritis

• AKA temporal arteritis.

Clinical

Features:

• Classic finding: jaw claudication, in a patient older than 50 years.
• Other findings: headache, vision loss or diplopia, scalp tenderness, polymyalgia, weight loss, chills, fever.

Work-up:

• CRP, ESR, temporal artery biopsy.

Treatment:

• Treat right away with high dose steroids.

Micrograph

Features:

• Classical: granulomas.

Takayasu's arteritis

General:

• Disease of medium/large arteries.
  • Classically involves the aortic arch (leading to decreased pulses in the upper limbs).
• Typically in patients <40 yrs old.
• Usually asian.

Microscopic

Features:

• Adventitial mononuclear infiltrate with perivascular cuffing of the vasa vasorum.
• Mononuclear inflammation in media.
• Granulomas, giant cells.
• +/-Patchy necrosis of media.

Polyarteritis nodosa

• Abbreviated PAN
• Involves small and medium sized vessels.
• Often - renal vessels, mesenteric vessels.
• Strong association with hepatitis B (see medical liver diseases); ~1/3 of patients with PAN have HBV.

Serology:

• ANCA is usually negative.

Microscopic

Features:

• Inflammatory cells (neutrophils, lymphocytes) within the tunica media.
• Necrosis: dead vessel wall - pink anucleate stuff, nuclear debris (black specks of nuclear material).

Wegener's granulomatosis

Clinical

• Epistasis.
• Renal failure - present as nephritic syndrome.
  • Renal biopsy: crescentic glomerulonephritis (AKA rapidly progressive glomerulonephritis).
• Pulmonary hemorrhage.

Serology:

• c-ANCA +ve.

Notes:

• Pulmonary hemorrhage syndromes:
  • Goodpasture syndrome.
  • Idiopathic pulmonary hemosiderosis.
  • Vasculitis-assoc. hemorrhage (hypersensitivity angiitis, Wegener's granulomatosis).
  • Systemic lupus erythematosus.

Microscopic

Features:

• Granulomas typically poorly formed.

Image: Wegener's granulomatosis (flickr.com).