The treatment of vasculitis depends primarily on whether it is primary or secondary. If an underlying cause can be identified (secondary vasculitis), treatment should be directed at the cause. Examples include withdrawal of a triggering drug or treatment of an underlying infection.
Since vasculitis results from an "overactive" immune system, treatment often involves drugs that suppress the immune system. The most commonly used drugs are corticosteroids, such as prednisone and methylprednisolone. Unfortunately, when used long term, they are associated with side effects such as weight gain, reduced bone density, and increased risk of diabetes and high blood pressure. In order to reduce the corticosteroid requirements and still control the disease, other immunosuppressive drugs such as cyclophosphamide, methotrexate, and azathioprine may be used.
The choice of drug for each patient should be decided after considering the severity of the disease. All immunosuppressive drugs carry an increased risk of infection and potential for reduction in blood cell counts. Frequent monitoring, using blood tests such as complete blood cell counts (CBC), liver function tests, and kidney function tests (creatinine, BUN, urinalysis), helps to detect such side effects early. The use of other medications, such as folic acid in patients taking methotrexate, can protect the individual from some of the side effects.