What is vasculitis and why does it cause red itchy hands and feet?

Vasculitis is an inflammation of the blood vessels. Inflammation is a condition in which tissue is damaged by blood cells entering the tissues. In inflammatory diseases, these cells are mostly white blood cells. White blood cells circulate and serve as our major defense against infection. Ordinarily, white blood cells destroy bacteria and viruses. However, they can also damage normal tissue if they invade it.

Vasculitis can affect

* very small blood vessels (capillaries),
* medium-size blood vessels (arterioles or venules), or
* large blood vessels (arteries or veins).


How Does Vasculitis Damage The Body?
Several things can happen to an inflamed blood vessel.

1. If it is a small vessel, it may break and produce tiny areas of bleeding in the tissue. These areas will appear as small red or purple dots on the skin.
2. If a larger vessel is inflamed, it may swell and produce a nodule which may be felt if the blood vessel is close to the skin surface.
3. The inside of the vessel tube may become narrowed so that blood flow is reduced.
4. The inside of the vessel tube may become totally closed, usually by a blood clot which forms at the site of inflammation.
5. If blood flow is reduced or stopped, the tissues which receive blood from that vessel begin to die.
* For example, a person with vasculitis of a medium-sized artery in the hand may develop a cold finger which hurts whenever it is used.
* Occasionally this can progress to gangrene.



What Causes Vasculitis?
Vasculitis can be caused by

1. infection of the blood vessel walls
* This is rare. When it occurs, bacteria, viruses or fungi infect the blood vessel.
* White blood cells move in to destroy the infectious agents and damage the blood vessel in the process.
* This is a serious condition and requires prompt antibiotic treatment.
2. an immune or "allergic" reaction in the vessel walls.
* This cause of vasculitis is more common.
* Substances which cause allergic reactions are called antigens.
* Antigens cause the body to make proteins called antibodies which bind to the antigen for the purpose of getting rid of it.

Antigen and antibody bound together are called immune complexes. Two primary ways in which immune complexes destroy antigens are:

1. by attracting white blood cells to digest the antigen
2. by activating other body substances to help destroy the antigens.

* Unfortunately, some immune complexes do not serve their purpose of destroying antigens. Instead, they remain too long in the body and circulate in the blood and deposit in tissues. They commonly accumulate in blood vessel walls, where they cause inflammation.
* It is likely that some white blood cells (cytotoxic cells) which kill infectious agents can also accidentally damage blood vessels and cause vasculitis.

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http://en.wikipedia.org/wiki/Vasculitis

Hello,
Found this for you so hope it helps.

The term vasculitis refers to a rare group of diseases that are characterised by the presence of inflammation in the blood vessels. in all types of vasculitis, the basic problem is that there is inflammation in the blood vessel wall. White blood cells infiltrate the vessel wall leading to damage of the surrounding tissue and obstruction of the vessel itself. Blood supply to vital tissues may then be impaired, leading to a potentially damaging effect on the organ which is being supplied. The severity of the illness generally depends on the site, size and extent of vessel involvement.

What causes vasculitis? On rare occasions it may be caused by an infection or drug therapy. There is no doubt that something causes the body鈥檚 defenses to start working against itself, instead of just the intruders. But in most people it can occur by itself where no cause has as yet been found.

Some people with vasculitis report that they always 鈥渓ook well鈥?even when they are feeling at their worst! (This may be a side effect of taking prednisolone, or just because the disease itself can be such a hidden one). If you know this applies to you, it would be helpful to remind your doctor of this whenever you are consulting him regarding new or ongoing medical problems. The severity of your symptoms may be underestimated if your doctor is unaware that how you look is not necessarily an accurate indicator of your real state of health.

symptoms may include unexplained weight loss, unexplained fever, skin lesions, muscle pain, joint pains, and mouth ulcers or genital ulcers that do not go away. Some symptoms are associated more with a particular form of vasculitis than others, such as sinus problems with Wegeners Granulomatosis and genital ulcers with Behcets disease. As you become more aware of how your vasculitis effects you as an individual, then you appreciate that worsening of these symptoms may be a sign of a flare.