15. Autoimmune disease: Patients with a history of inflammatory bowel disease (including Crohn's disease and ulcerative colitis) and autoimmune disorders such as rheumatoid arthritis, autoimmune thyroiditis, autoimmune hepatitis, systemic progressive sclerosis [scleroderma and variants], Systemic Lupus Erythematosus, autoimmune vasculitis [e.g., Wegener's Granulomatosis] or autoimmune neuropathies (such as Guillain-Barre syndrome) are excluded from this study. Vitiligo and adequately controlled endocrine deficiencies such as hypothyroidism are not exclusionary.