Main Article: Vasculitis;

Vasculitis refers to inflammation of vessels including arteries and veins that contain blood and blood contains the inflammatory cells including white blood cells e.g. Neutrophil granulocytes, eosinophil, basophils and mast cells. White blood cells contain granules (sac) contain toxic substances and digestive enzymes in order to eliminate harmful stimuli. Now question is what is inflammation?

 Inflammation is the complex biological response of the vascular tissues to harmful stimuli, such as pathogen, damaged cells, and irritant or a protective immunovascular response in order to eliminate the initial cause of cell injury and to initiate the tissue repair. It is considered as innate immunity, compared to adaptive immunity that is specific for each pathogen to eliminate. All Tissues are supplied by blood vessels and nerves. Tissue takes nutrient, oxygen and other substance from blood vessels to survive. Now the question is from where do blood vessels get the nutrient and oxygen? Get oxygen from respiratory system and nutrient from foods through GIT. One new question you need to know, otherwise the question will be existing in your mind as confused and unable to satisfy, who produces the white blood cells? The Bone marrow is responsible for production of WBCs. Now you need to go into depth about mechanism of inflammation. Inflammation caused by infections, trauma, or unknown like autoimmune. Vasculitis caused by unknown like autoimmune is the main topic here. White blood cells are considered as immune cells. Once tissue has been attacked by unknown etiology that is similar to human tissue,

our immune system produces antibody against that unknown etiology in order to destroy etiology but it is similar to tissue that is why it destroy the tissue and vessels, this condition is called autoimmunity. Here our immune cells are unable to recognize own tissue that is affected. Antibody, Neutrophil and other cells if needed go to target tissue through blood circulation then cross the endothelium of blood vessels through vasodilatation caused by histamine and deposited over the target tissue then release their toxic substance and digestive enzyme in order to eliminate etiology without harming their own tissue but etiology is similar to tissue and affect the blood vessels from outside as a result narrowing lumen of vessels lead to ischemia; blood flow obstruction.

Pictures show mechanism of inflammation of the blood vessels.

There are three sizes of arteries are small sized, medium sized and large sized all over the body including lungs, kidneys, heart, head, eyes, GIT and legs.

Main pathogenesis: Immune complexes, antibody, cytokines and granulomatosis.

Classification of vasculitis, based on size of involved vessels:

Large vessel	Medium vessel	Medium to small vessel	Small vessel
1.       Giant cell arteritis	1.       Polyarteritis nodosa	1.       Wegner’s granulomatosis	a.       Henoch-schonlein purpura
2.       Takayasu’s arteritis	2.       Kawasaki disease and	2.Churg-strauss syndrome	b.Cryoglobulinemic vasculitis
	3.       Hepatitis B virus related	3.       Microscopic polyangitis	C.Cutaneous leukocytoclastic vasculitis.

Most important is to diagnose the vasculitis through systemic sign and symptoms and through biopsy of the infected blood vessels, and also through presence of antibody in the blood whatever the name of the diseases because the management depends on underlying cause is autoimmunity.

Symptoms of vasculitis:

 No specific symptoms are fever, fatigue, malaise, anorexia, and weight loss.          

Mucocutaneous symptoms: mouth ulcer, Reynaud’s phenomenon, vasculitis purpura, and skin rash

Mononeuritis multiplex, ischemic renal failure related to arthritis, or glomerulonephritis, arthralgia, arthritis, or myalgia, hematuria, and asthma.

How to reach to a diagnosis of vasculitis? You need to exclude other conditions that stimulate vasculitis and conditions which can cause secondary vasculitis.

A.      Conditions that stimulate vasculitis are 1. Atherosclerosis, 2. Fibro muscular dysplasia, 3. Vascular spasm, 4. Embolic conditions and 5. Thrombophilia.

B.      Conditions which can cause secondary vasculitis are 1. Connective tissue disease, 2. Malignancy, 3. Drugs, 4. Hepatitis B and C, and 5. Cryoglobulinemia.

After excluding above, case need some test to identify and confirm the class of vasculitis.

Investigation:

Biopsies.

      Laboratory: Anti-Neutrophil Cytoplasmic Antibodies (ANCA), rheumatoid factor, serum cryoglobulins,

CBC, ESR, CRP, urine analysis, renal function test, hepatic enzymes, viral serology and blood cultures.

    Vascular imaging:

         Duplex: describes the flow, velocities and the presence of narrowing or aneurysms.

       Angiography: is the most diagnostic and also CT, MRI angiography.

Other imaging according to organ involvement: like X-ray CT scan for the chest and paranasal sinuses, echocardiography, abdominal ultrasonography, and EMG and nerve conductions studies.

Now is the treatment:

 Treatment is planned according to the type and severity of organ involvement, the aggressive nature of the disease, and the specific type of vasculitis.

Corticosteroids are the mainstay of treatment for the vasculitis due to it kills all the pathology related to vasculitis. The dose is chosen according to disease severity and also combination with cyclophosphamide.

How to diagnose the type of vasculitis from symptoms and test:  abdominal pain during eating most probably mesenteric vessels involvement, stroke or blurring vision suggest carotid or temporal arteries involvement, associated with asthma most probably upper respiratory vessels involvement, angina mostly coronary artery involvement, claudicating during chewing most probably external carotid arteries involvement . According to size and site of vessels involvement give the name of diseases. In case of vasculitis, most important is to diagnose the vasculitis.