Crohn disease, a well-known subtype of inflammatory bowel disease, is an inflammatory condition of the gastrointestinal tract with numerous possible extra-intestinal manifestations. Approximately 40% of all patients affected by Crohn disease experience at least one extra-intestinal manifestation of the disease, with the skin being the most common site of extra-intestinal involvement. Other common locations of extra-intestinal involvement include the eyes, joints, and hepatobiliary system. Interestingly, an extra-intestinal manifestation may precede the formal diagnosis of Crohn disease in about 25% of patients.