The exact cause of vasculitis isn't fully understood. Some types are related to a person's genetic makeup. Others result from the immune system attacking blood vessel cells by mistake. Possible triggers for this immune system reaction include:
• Infections, such as hepatitis B and hepatitis C
• Blood cancers
• Immune system diseases, such as rheumatoid arthritis, lupus and scleroderma
• Reactions to certain drugs
• Age: Giant cell arteritis rarely occurs before the age of 50, while Kawasaki disease is most common in children younger than 5 years old.
• Family history: Behcet's disease, granulomatosis with polyangiitis and Kawasaki disease sometimes run in families.
• Lifestyle choices: Using cocaine can increase your risk of developing vasculitis. Smoking tobacco, especially if you're a man younger than 45, can increase your risk of Buerger's disease.
• Medications: Vasculitis can sometimes be triggered by medications such as hydralazine, allopurinol, minocycline and propylthiouracil.
• Infections: Having hepatitis B or C can increase your risk of vasculitis.
• Immune disorders: People who have disorders in which their immune systems mistakenly attack their own bodies may be at higher risk of vasculitis. Examples include lupus, rheumatoid arthritis and scleroderma.
• Sex: Giant cell arteritis is much more common in women, while Buerger's disease is more common in men.
Courtesy: Mayo Clinic