Blood vessels run through the entire body - from the large aorta, through the tiny capillaries in the tissue, to the veins that carry the blood back to the heart. It is easy to imagine that vascular changes can lead to a variety of disorders of various organs.
What is vasculitis?
Vasculitis (plural: vasculitis) is a term that includes many quite different, fortunately rare diseases that have one thing in common: It comes to inflammatory changes in blood vessels.
Almost all vasculitides belong to the autoimmune diseases, so are triggered by misguided immune system reactions against the body's own tissue and also referred to as immune vasculitis. Rarely, the inflammation can also be caused by an infection of the vessels, for example by bacteria or fungi.
What forms of vasculitis are there?
In principle, those skilled in the art differentiate primary forms that directly affect the vessels, and secondary forms in which the vessels are involved in other diseases (for example, collagenosis, AIDS) or react to certain drugs. Since the symptoms mainly depend on which blood vessels (and to what extent) are affected, the primary forms have been divided accordingly since 1992 and the individual clinical pictures (with partially adventurous names) sorted below:
- Small vessel vasculitis: either with certain autoantibodies (ANCA) - including Wegner's granulomatosis, Churg-Strauss syndrome, and microscopic panarteritis (mPAN) - or without ANCA, ie, Schönlein-Henoch purpura, cryoglobulinemia, and leukocytoplasmic vasculitis
- Vasculitis of medium-sized vessels: panarteritis nodosa (cPAN), Kawasaki syndrome
- Large-vessel vasculitis (giant cell arteritis): giant cell temporal arteritis (which combines the two diseases, polymyalgia rheumatica and temporal arteritis Horton), Takayasu's arteritis.
Necrotizing vasculitis and Raynaud's syndrome
If the inflammation leads to the destruction of the vessel walls and the occlusion of the blood vessels with the death (necrosis) of the surrounding tissue, one speaks of a necrotizing vasculitis. It is particularly prevalent in small vessel ANCA vasculitis and in panarteritis nodosa, and the course and prognosis are worse than in the other forms.
Vasculitis can also lead to vascular spasm, the secondary Raynaud's syndrome, especially in cold weather. The result is the whitening or blushing of the fingers (dome) or the whole hand. This is common in smokers suffering from thrombangiitis obliterans (Winiwarter-Buerger syndrome), an inflammation that takes place in individual sections of the vessel leading to blood clots with vascular occlusions.
How does the vasculitis develop and who is affected?
As before, the exact causes are unknown. Presumably, external factors such as infection with viruses (for example, influenza or viral hepatitis) play a role in causing immune reactions and the resulting inflammation in people with a specific genetic susceptibility.
Interestingly, many of the diseases predominantly occur in certain populations - such as Kawasaki syndrome and Schönlein-Henoch purpura in childhood, Takayasu's arteritis in younger women, polyarteritis in middle-aged men, giant cell temporal arteritis in older people.