Vasculitis means inflammation of the blood vessels. This inflammation can damage the lining of the vessel and sometimes reduce blood flow or completely block it.
Although the causes of most types of vasculitis aren't known, an autoimmune disease may play a role. This is when the immune system mistakenly attacks the body's own tissues. Allergic reactions, infection with a virus, or even damage to blood vessels from the sun's radiation may cause vasculitis.
There are several types of vasculitis. Each is distinguished by the size of the blood vessels involved, the organs involved, and the presence of antibodies called antineutrophil cytoplasmic antibodies (ANCAs).
Takayasu arteritis affects women under the age of 40 almost exclusively. Inflammation occurs in large blood vessels such as the artery leaving the heart (the aorta). People with this type of arteritis may feel weak, dizzy, and light-headed and have severe muscle pain. The arteries to the arms and legs can become so narrowed from the arteritis that it can be impossible to feel a pulse in the arms or legs, despite normal blood pressure.
Temporal arteritis affects medium to large vessels that supply blood to the head. When the inflammation targets the arteries in the neck, upper body, and arms, it is called giant cell arteritis.
Polyarteritis nodosa affects small and medium-sized arteries. Several groups of blood vessels may be affected, including the arteries that serve the kidneys, intestines, and heart. Exposure to the hepatitis B virus has been strongly implicated as a cause of polyarteritis nodosa in some people. Polyarteritis nodosa is one of the few immune system diseases in which more men are affected than women.
Wegener granulomatosis is a rare form of vasculitis in which inflammation targets the blood vessels in the lungs, sinuses, and kidneys. Symptoms include coughing, a bloody discharge from the nose, breathing difficulty, chest pain, and blood in the urine. The ANCA test result is often positive.
Damage to blood vessel walls causes a slowdown in delivery of blood and oxygen to the tissues that the vessels supply. That harms those tissues, and the body systems that are supported by them. Consequently, the symptoms of vasculitis vary dramatically. Symptoms can include:
- aching muscles and joints
- loss of appetite
- nerve damage or muscle weakness
- high blood pressure
- skin ulcers
- abdominal pain
- blood in the stool.
Your doctor can diagnose polyarteritis nodosa by performing a biopsy or by angiography, in which dye is injected into blood vessels so that any abnormalities can be seen on x-rays.
Treatment depends on the size, extent, and location of the affected blood vessels. The first step is to identify and remove things that might be causing the immune reaction, such as a new medication. In some cases, the vasculitis disappears without treatment.
Most types of arteritis respond well to corticosteroid drugs and immunosuppressive drugs. Other therapies include:
- immunosuppressive drugs to treat Wegener granulomatosis
- antiviral drugs to treat polyarteritis nodosa caused by hepatitis B
- surgery to treat advanced forms of Takayasu arteritis
- antibiotic drugs to treat skin vasculitis caused by bacteria.