REEL 4

Skip lesions are a characteristic feature of Crohn's disease, an inflammatory bowel disease. Unlike ulcerative colitis, Crohn's disease can occur anywhere in the gastrointestinal tract except the rectum. The disease is caused by CD4 positive Th1 subset cells, leading to granuloma formation. The HLA associated with Crohn's disease is HLA-DR1. Pathologically, Crohn's disease presents with patchy pseudopolyps, creeping mesenteric fat, a cobblestone appearance of the GI tract, and a "host pipe" narrowing. All four layers of the GI tract have ulceration. तो यार स्किपिंग तो तुमने देखी होगी नहीं। बट स्किप लीजिन कहा मिलते हैं। चलो देखते हैं। So, skip lesions are seen in the Crohn's disease. Crohn's disease is a type of an inflammatory bowel disease. अब इसका कजन है ulcerative colitis, which is also in form of the inflammatory bowel disease. So, the Crohn's disease occurs anywhere in the GI tract, but the rectum is usually spared. The cells responsible for the Crohn's disease are the CD4 positive and in it, the Th1 subset cells. As a result of the Th1 subset cells, there is a formation of the granuloma. The HLA associated with the Crohn's disease is HLA-DR1. The most common site is the terminal ileum. Now, it's pathology. So, in Crohn's disease, skip lesions are seen. That is, they are not close to each other, but there is some distance between them. There is patchy pseudopolypsine. There is creeping mesenteric fat, which is seen in this image, which is as follows. There is a cobblestone appearance of the GI tract. And also, there is the host pipe appearance. Host pipe appearance means there is the narrowing of the GI tract. And all the four layers have ulceration, that is the mucosa, submucosa, serosa and the muscularis.