[Extra-intestinal Manifestations of chronic inflammatory Bowel diseases]

Approximately one third of all patients with Crohn's disease and ulcerative colitis suffer from extra-intestinal manifestations of their inflammatory bowel disease. Most commonly those symptoms occur simultaneously with the CED symptoms; they can, however, either precede them or appear later on in the course of the disease. The most frequent extra-intestinal symptoms are arthralgias of peripheral joints and spine, which are usually bland and self-limiting, while ankylosing spondylitis and erosive arthritides are rare. Skin lesion and eye affections can also parallel the bowel condition, but occasionally they precede intestinal manifestations and can be a first diagnostic clue. In addition, different extra-intestinal symptoms tend to simultaneously co-occur more frequently in some patients with CED, while others are not affected at all. Immunogenetic parameters play a role for the manifestations of the pathologic immune response both in the gut and in the musculo-skeletal systems, as indicated by associations with MHC class I alleles. Enteropathic microorganisms are also thought to be involved in the pathogenetic mechanisms.