Vasculitis is inflammation of the blood vessels. It happens when the body's immune system attacks the blood vessel by mistake. It is rare disease. Vasculitis can affect arteries, veins and capillaries. Arteries are vessels that carry blood from the heart to the body' organs. Veins carry blood back to the heart. Capillaries are smallest blood vessels that connect the small arteries and veins. Vasculitis are 3 types- based on size of vessel inflamed, which varies in symptoms, severity and duration

Large vessel vasculitis- Takayasu arteritis, gaint cell arteritis
Medium vessel vasculitis – Kawasaki disease, PAN (Polyarteritis Nodosa)
Small vessel vasculitis- Wegners (GPA), churgstrauss, HSP etc.
Most types of vasculitis are rare, and the causes are generally unknown. Vasculitis affects persons of both sexes and all ages. Vasculitis can be mild or severe, or even leads to death. Patients can have one episode of vasculitis or repeated episodes over years. A few forms of vasculitis affect certain age groups only. Example Kawasaki disease occurs only in children. IgA Vasculitis (Henoch-Schönlein) is much more common in children than adults. giant cell arteritis occurs only in adults over 50 years old. Vasculitis leads to poor blood flow to organs, such as the lungs, nerves, kidney and skin. Thus, vasculitis has a wide range of signs and symptoms, such as:

Shortness of breath and cough, blood in sputum
Tingling,numbness or weakness in a hand or foot
Red spots on the skin (“purpura”), lumps (“nodules”) or ulcers
On the other hand, vasculitis of the kidneys may produce no symptoms at first but is still a serious problem

What causes vasculitis?
We do not know exact causes most types of vasculitis. Some cases of vasculitis are due to autoimmune phenomenon, reactions to medicines, long-term infections (hepatitis C or hepatitis B virus) Sometimes vasculitis may be a part of other rheumatic diseases like lupus, rheumatoid arthritis and Sjögren’s syndrome.

Diagnosis of vasculitis
Clinical examination with support of lab test and biopsy aids in diagnosis of vasculitis

Blood tests- ANCA, CBP, ESR, CRP, urine examination, Renal function test, viral markers
Biopsy—surgical removal of a small piece of tissue for inspection under a microscope
Angiography—a type of CT/MRI to look for abnormalities of blood vessels
To find small-vessel vasculitis, we most often do a biopsy of the skin or a kidney. Detection of medium-vessel vasculitis happens by either biopsy (of skin, nerve or brain) or angiography. Angiography also is the test that often finds large-vessel vasculitis. A few forms of vasculitis, such as Behçet’s disease and Kawasaki disease, are usually detected based on a collection of clinical findings rather than biopsy or angiography. A positive ANCA test can help detect these types of vasculitis: granulomatosis with polyangiitis (Wegener’s), microscopic polyangiitis or eosinophilic granulomatosis with polyangiitis (Churg-Strauss).