True regarding Crohn's disease are all except

The skin involvement in Crohn's disease causes erythema nodosum, scleroderma does not occur in Crohn's disease. Other extraintestinal manifestations of Crohn's disease: 1. Migratory polyarthritis            2. Sacroiliitis  3. Ankylosing spondylitis     4. Uveitis 5.. Hepatic pericholangitis         6. Primary sclerosing cholangitis 7. Clubbing