Patients enrolled in this protocol will undergo a history, physical examination, and laboratory evaluation. Since vasculitis is multi-system disease with variable patterns of organ involvement, patients may undergo further comprehensive evaluation of a particular affected organ system when clinically indicated. Peripheral blood samples will be collected from affected patients, unrelated healthy volunteers matched for age, sex, and ethnicity whenever possible, and in some cases unaffected family members to help identify and study the genes involved in vasculitis and their functions. We may ask some patients to undergo nasal biopsy and additional imaging studies for research purposes. For a small number of patients and family members, we may ask permission to perform whole genome or exome sequencing. Successful completion of these studies will improve our understanding of disease pathogenesis.