As of Saturday, May 18, 2013
DEAR DOCTOR K: My father recently saw his doctor, complaining of fever, fatigue, joint pain and rashes. His doctor suspects vasculitis. What is vasculitis? How is it diagnosed and treated?
DEAR READER: Vasculitis is an inflammation of the blood vessels. This inflammation can be severe enough to reduce blood flow to tissues and organs. We don’t know for sure what causes it, but scientists believe it is an autoimmune disease. For some reason, the immune system mistakenly attacks the blood vessels, causing them to become inflamed. Under the microscope, you can see immune system cells next to the walls of blood vessels, and the walls have been damaged (presumably by the attack).
There are many different types of vasculitis, affecting blood vessels of different sizes and in different locations. The various forms also differ by the age at which they typically begin and the symptoms they cause. Following are the types of vasculitis your father may be dealing with:
— Giant cell arteritis (temporal arteritis) affects medium to large arteries, including those around the scalp, face, eyes. This type also affects the aorta as it branches from the heart, up into the neck and head.
— Takayasu arteritis affects the body’s biggest artery, the aorta, and its main branches.
— Polyarteritis nodosa affects small- to medium-sized blood vessels, especially in the skin, intestines, kidneys and nerves.
— Kawasaki disease is particularly likely to involve the arteries of the heart. It occurs mainly in children and can cause fatal heart attacks in young children.
— Hypersensitivity vasculitis affects the smallest blood vessels, especially those in the skin. It is triggered by an allergy, particularly to a drug.
— Granulomatosis with polyangiitis (Wegener’s) affects small- and medium-sized blood vessels in the kidneys and in the upper and lower respiratory tract.
— Vasculitis due to rheumatologic diseases. The two most common of these diseases to produce vasculitis are systemic lupus erythematosus (lupus) and rheumatoid arthritis.
— Vasculitis due to infection. Certain viruses cause vasculitis. Two examples are hepatitis B and hepatitis C virus.
The most accurate way to diagnose vasculitis is with a tissue biopsy. The doctor removes a small tissue sample from an organ (such as skin, muscle, nerve or kidney) to be examined in a laboratory.
Before a biopsy, however, the doctor is likely to do some less invasive tests. These may include blood tests to check for inflammation, immune system activity, and liver and kidney function. Urine analysis may also be done to evaluate possible kidney problems.
The main treatment for most types of vasculitis is prednisone. This corticosteroid works by reducing inflammation. Additional treatments depend on the form of vasculitis. For example, a doctor may treat giant cell arteritis with an immune-suppressing medication.
The intensity and duration of the treatment depends on the type and cause of the vasculitis. The good news is that most cases of vasculitis can be treated successfully.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.