Еxtraintestinal manifestations of inflammatory bowel disease

Inflammatory bowel diseases, that include Crohn's disease and ulcerative colitis, are considered systemic processes since their symptoms and manifestations are not limited to the gastrointestinal tract. Extraintestinal manifestations are characteristic of inflammatory bowel disease and can be observed in almost every system of the patient’s body. Extraintestinal symptoms are present in approximately 42 % of patients with inflammatory bowel disease during the manifestation of the pathological process. They can also precede the onset of gastrointestinal symptoms. Nowadays, the pathogenesis of extraintestinal manifestations of inflammatory bowel disease is not completely obvious. It is currently believed that the mucous membrane of the patient's gastrointestinal tract can provoke an immune response in the extraintestinal areas due to the presence of common epitopes in individuals with a genetic predisposition. Extraintestinal symptoms are most often observed in the joints (peripheral and axial arthropathy), skin (nodular erythema, gangrenous pyoderma, aphthous stomatitis), visual organ (episcleritis, uveitis) and hepatobiliary system (primary sclerosing cholangitis). Other organs and systems of the body, such as the lungs, kidneys, pancreas and venous system, are also affected; however, their damages are much less common. Some extraintestinal manifestations, for instance arthritis of several joints, erythema nodosum, episcleritis, and aphthous ulcers of the oral cavity, are associated with inflammatory activity in the intestine. Other extraintestinal symptoms, such as uveitis and ankylosing spondylitis, are not associated with inflammatory bowel disease activity. Manifestations like primary sclerosing cholangitis and gangrenous pyoderma may or may not be associated with inflammatory bowel activity. Extraintestinal manifestations of inflammatory bowel disease exacerbate the negative impact of the pathological process on the patient's quality of life, and some of them, such as venous thromboembolism, can be life-threatening.