Causes of wegeners granulomatosis and treatment?

Autoimmune disease: Like all autoimmune diseases, the cause is not really known, but likely a combination of genetic factors and environmental exposures (e.g., infections, chemicals, pollutants). Treatment depends on how severe disease it is. Typically steroids (e.g. Prednisone) and if severe, Cytoxan or rituxan (rituximab). If limited disease (just nasal/upper airway involvement), Methotrexate may be sufficient.