What Are the Causes of Vasculitis?

The causes of vasculitis, or inflammation of the blood vessels, can include infections, cancers, and allergic reactions. Environmental factors can also cause the condition. Commonly, the causes of vasculitis are due to the immune system attacking the cells of the blood vessels. There are several different types of vasculitis, which have different causes and symptoms.

Vasculitis can either occur on its own, which is known as primary vasculitis, or along with another condition. In a lot of cases, the exact cause of vasculitis is unknown. What is known is that the condition causes the blood vessels to become thick, causing the flow of blood to slow or even stop.

Behcet's syndrome is one type of vasculitis. Usually, the syndrome affects young people in their 20s or 30s, particularly men. There are several possible causes of vasculitis in this instance. Behcet's syndrome may be caused by a gene, the HLA-B51 gene. It may also be triggered by exposure to a virus or to bacteria. Typically, people who have Behcet's have an abnormal immune system as well.

Another type of vasculitis, Buerger's disease, or thromboangiitis obliterans, is commonly caused by smoking or heavy chewing tobacco use. This form of vasculitis usually affects men in their late 30s or 40s. It can affect children as well, especially if they suffer from an auto-immune disorder, although this is much more rare.

Generally, auto-immune disorders are common causes of vasculitis. Diseases such as lupus or scleroderma increase a person's risk of inflammation of the blood vessels. Another form of immune response, an allergic reaction, can also trigger vasculitis.

Infections are other causes of vasculitis. An infection such as hepatitis C can cause cryoglobulinemia, which is a blood protein that turns to gel when the blood is exposed to temperatures below normal body temperature. Cryoglobulinemia leads to vasculitis in many cases. It can also be caused by auto-immune disorders and cancers of the blood, such as leukemia.

Henoch-Schönlein purpura is a type of vasculitis that can be caused by an increased immune response to infections. A patient who has Henoch-Schönlein purpura has an overactive immune system that continues to attack the cells of the body long after the infection has been cured. The signs of the condition include a rash on the buttocks and legs that usually looks like a collection of small bruises. Henoch-Schönlein purpura can also be caused by cold weather or vaccinations. Some patients may show signs of it after an insect bite or if they eat a certain food.