Vasculitis is essentially an inflammation of the vessel wall. It can be either infectious or non-infectious (autoimmune).
Generally, "vasculitis" is often mentioned on its own, referring to the latter (non-infectious) form. It is classified based on the vessel size (large vessels such as the aorta and its branches, medium vessels, and small vessels).
Mechanisms
- Immune complex deposition
- Neutrophil-mediated (ANCAs; pauci-immune)
- Anti-endothelial activity
Large vessel vasculitides
Both giant cell and Takayasu arteritis are associated with lymphocytic migration and proliferation in the adventitia of vessels, cytokine secretion, macrophage recruitment, and formation of granulomas resulting in the destruction of the vessel wall and its occlusion.
Giant cell (temporal) arteritis
Giant cell arteritis (also known as temporal arteritis or Horton disease) affects large arteries in the head and neck, typically the occipital or temporal arteries.