Giant (multinucleate) cells, a common finding in the lesions of Crohns disease, are less common in the lesions of lichen nitidus. Classification
Crohns disease is one type of inflammatory bowel disease (IBD). It typically manifests in the gastrointestinal tract and can be categorized by the specific tract region affected. A disease of both the ileum (the last part of the small intestine that connects to the large intestine), and the large intestine, Ileocolic Crohns accounts for fifty percent of cases. Crohns ileitis, manifest in the ileum only, accounts for thirty percent of cases, while Crohns colitis, of the large intestine, accounts for the remaining twenty percent of cases and may be particularly difficult to distinguish from ulcerative colitis.Gastroduodenal Crohns disease causes inflammation in the stomach and the first part of the small intestine called the duodenum. Jejunoileitis causes spotty patches of inflammation in the top half of the small intestine, called the jejunum. The disease can attack any part of the digestive tract, from mouth to anus. However, individuals affected by the disease rarely fall outside these three classifications, with presentations in other areas.Crohns disease may also be categorized by the behavior of disease as it progresses. These categorizations formalized in the Vienna classification of the disease. There are three categories of disease presentation in Crohns disease: stricturing, penetrating, and inflammatory. Stricturing disease causes narrowing of the bowel that may lead to bowel obstruction or changes in the caliber of the feces.
Crohns disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension, and weight loss. Complications outside of the gastrointestinal tract may include anemia, skin rashes, arthritis, inflammation of the eye, and fatigue. The skin rashes may be due to infections as well as pyoderma gangrenosum or erythema nodosum. Bowel obstruction may occur as a complication of chronic inflammation, and those with the disease are at greater risk of colon cancer and small bowel cancer.While the precise causes of Crohns disease (CD) are unknown, it is believed to be caused by a combination of environmental, immune, and bacterial factors in genetically susceptible individuals. It results in a chronic inflammatory disorder, in which the bodys immune system defends the gastrointestinal tract, possibly targeting microbial antigens. While Crohns is an immune-related disease, it does not appear to be an autoimmune disease (in that the immune system is not being triggered by the body itself). The exact underlying immune problem is not clear; however, it may be an immunodeficiency state.About half of the overall risk is related to genetics, with more than 70 genes having been found to be involved. Tobacco smokers are twice as likely to develop Crohns disease as nonsmokers. It also often begins after gastroenteritis. Diagnosis is based on a number of findings, including biopsy and appearance of the bowel wall, medical imaging, and description of the disease.