IBD Flashcards
UC and CD?
- ULCERATIVE COLITIS AND CROHN’S DISEASE
Ulcerative colitis is a diffuse mucosal inflammation limited to the colon; it almost always affects the rectum, and it may extend proximally in a symmetrical, uninterrupted pattern to involve all or part of the large intestine. Crohn’s disease, by contrast, is a patchy transmural inflammation that may involve any part of the gastrointestinal tract from mouth to anus.
characteristics of UC?
- CHARACTERISTIC FEATURES OF ULCERATIVE COLITIS
The typical pattern of ulcerative colitis is chronic inflammation limited to the mucosa of the colon, occurring in a continuous symmetrical distribution from the rectum proximally to all or part of the rest of the large bowel.
anatomy of UC?
- ANATOMIC EXTENT OF ULCERATIVE COLITIS
At least half of all cases of ulcerative colitis in the community at large are limited to the rectum (proctitis) or rectosigmoid (proctosigmoiditis). About 10% of all cases may present initially involving the entire large bowel (universal or pancolitis). Intermediate distributions are usually characterized as left-sided (involving the descending colon up to but not beyond the splenic flexure) or extensive (extending proximal to the splenic flexure). It is estimated that 10-30% of cases that are initially confined to the rectosigmoid or descending colon may ultimately spread further proximally with a worsening clinical course.
• Farmer RG, Easley KA, Rankin GB. Clinical patterns, natural history, and progression of ulcerative colitis: a long-term follow-up of 1116 patients. Dig Dis Sci 1993;38:1137-46.
endoscopic UC?
- ENDOSCOPIC SPECTRUM OF SEVERITY
In the normal colon, the mucosa is a shiny, pale pink and retains a delicate, reticulated vascular pattern. In mild ulcerative colitis, the mucosa becomes duller and redder, often with a “granular” or fine sandpaper-like texture, and the vascular pattern is obscured. In moderate cases, gross pitting of the mucosa is seen and the lining may crumble away and bleed at the lightest touch (friability). The most severe instances will demonstrate macroulceration with mucopurulent exudate and spontaneous hemorrhage
symptoms of UC?
bleeding
diarrhoea (not present in proctitis)
urgency
abdominal pain
toxic colitis?
- TOXIC COLITIS
The most dangerous acute complication of ulcerative colitis occurs when the ulcerating, inflammatory process dissects deeply through the wall of the colon, producing a serositis and paralytic ileus. An early radiologic sign of this severe “toxic” colitis is an accumulation of gas over a long segment of colon, as seen on plain films of the abdomen (left panel). At this point, the luminal diameter need not be increased; in fact, it may even be narrowed with tubular or scalloped margins due to edema and spasm.
The more classic appearance of toxic dilatation or “megacolon” (right panel) does not usually emerge until late stages of the process, by which time the patient is already in imminent danger of perforation and/or peritonitis. The dilatation is often maximal in the transverse colon because its superior location in the supine patient allows air to collect in this segment of the flaccid bowel. (Rotation of the patient from supine to prone therefore helps redistribute the gas and decompress the colon.) A characteristic radiologic finding demonstrated in this case of toxic dilatation is the protrusion of soft tissue densities into the lumen, representing a combination of pseudopolyps and submucosal edema. The haustra are also abnormal — either obliterated as in this case, or occasionally accentuated. Barium enema and colonoscopy in such patients carry great risks in this situation and are usually contraindicated.
perforation?
- PERFORATION
The potentially most lethal complication of toxic colitis is perforation. An early sign of bowel necrosis and impending perforation is subserosal dissection of luminal gas into the bowel wall, visible on this plain film of the abdomen (left panel) as sharply defined linear lucencies paralleling the medial wall of the ascending colon. The CT scan (right panel) demonstrates both a curvilinear air collection in the bowel wall and an adjacent collection of extraluminal air.
Clinical signs and symptoms in such cases may be subtle or absent; even as severe a complication as free perforation of the colon may be clinically silent in patients receiving corticosteroids.
colonoscopic surverillance?
- COLONOSCOPIC SURVEILLANCE FOR DYSPLASIA
In the search for “early warning signals” of impending malignant transformation, cellular atypia or dysplasia on colonoscopic biopsy has been reported to be a useful sign. Although experience is far from uniform, some series report at least a 50% association of occult malignancy with high-grade dysplasia (lower left panel). For dysplasia to be a reliable warning sign of cancer, however, it is essential that the finding be made independent of severe inflammation (upper left panel). This slide emphasizes the importance, in any program of colonoscopic surveillance for dysplasia, of trying to obtain biopsies from relatively normal areas (solid image in right panel), away from the most grossly inflamed areas of mucosa (dotted image in right panel).
• Riddell RH, Goldman H, Ransohoff DF et al. Dysplasia in inflammatory bowel disease: standardized classification with provisional application. Hum Path 1983;14:931-968.
IBD IBS diff diagnosis?
extraintestinal manifestations?
apthous stomatitis, episcleritis and uveitis, arthritis, vacular complications, E. nodosum. P gangrenosum
peripheral arthritis?
- PERIPHERAL ARTHRITIS
The most common extracolonic manifestation of colitis is a peripheral arthritis that usually affects knees, ankles, wrists, and fingers. The joint inflammation superficially mimics rheumatoid arthritis, but differs in the six principal characteristics listed on the right of the slide. This “colitic arthritis” generally parallels the activity of the underlying inflammatory bowel disease.
- Brynskov J, Binder V. Arthritis and the gut. Eur J Gastroenterol Hepatol 1999;11:997-9.
- Veloso FT, Carvalho J, Magro F. Immune-related systemic manifestations of inflammatory bowel disease: a prospective study of 792 patients. J Clin Gastroenterol 1996;23:29-34.
extra-intestinal complications unrelated to diseae activity
Central (axial) arthropathy:
- Ankylosing spondylitis (associated with HLA B27)
- Sacro-iliitis
Liver disease:
- primary sclerosing cholangitis
central arthritis?
- CENTRAL (AXIAL) ARTHRITIS
Ankylosing spondylitis and sacro-iliitis frequently accompany colitis, although these complications may be detected on x-ray without producing clinical symptoms. In spondylitis, syndes-mophytes bridge the vertebral bodies laterally (AP view, left panel) and anteriorly (lateral view, right panel). Sclerosis of the corners of the vertebral bodies is also visible in the lateral view. The sacro-iliitis results in sclerosis and obliteration of the sacroiliac joints (AP view, left panel).
These central arthritic complications do not parallel the activity of the colitis, but follow an independent course, sometimes preceding the onset of the colitis and often progressing even following total colectomy, as in this case. Note surgical clips showing an ileal pouch or reservoir in the pelvis, proximal to an ileoanal anastomosis. Ankylosing spondylitis and sacro-iliitis tend to occur most often in colitis patients with the HLA haplotype B27.
• de Vlam K, Mielants H, Cuvelier C, De Keyser F, Veys EM, De Vos M. Spondyloarthropathy is underestimated in inflammatory bowel disease: prevalence and HLA association. J Rheumatol 2000;27:2860-5.
sclerosig cholangitis?
- SCLEROSING CHOLANGITIS
In the film on the left, the changes in the bile ducts are largely confined to the intrahepatic ducts which are distorted, truncated and have segmental areas of narrowing and beading. Isolated intrahepatic ductal involvement on radiologic studies is the presenting manifestation of sclerosing cholangitis in only about 15-20% of cases. Some contrast is seen entering the cystic duct and gallbladder, which is not well filled. The film on the right demonstrates more extensive intrahepatic and extrahepatic biliary involvement with segmental narrowing and dilatation seen in both common bile duct and right hepatic ducts. The left hepatic ducts are not filled out because of a high grade stricture of the duct above the confluence of left and right ducts. Cholecystectomy clips are noted and the pancreatic duct is also filled.
anatomical distribution of crohns?
- ANATOMIC DISTRIBUTION
Crohn’s disease may affect any part of the alimentary tract from mouth to anus. About one-third of cases are confined to the small bowel (“regional enteritis”), usually involving the terminal ileum (“ileitis”). Nearly half of all cases involve both small and large bowel (“ileocolitis”), usually in continuity. About 20% of cases are confined to the colon alone. Perianal lesions occur in approximately one-third of patients, but are only rarely the presenting or sole site of Crohn’s disease. Oral and gastroduodenal lesions are also commonly found when carefully sought, but are clinically important in only a minority of cases.
clinical patterns of crohns?
- CLINICAL PATTERNS
Most cases of Crohn’s disease present clinically with local manifestations of intestinal inflammation, but they tend over time to evolve into clinical patterns that are primarily stricturing (obstructive) or penetrating (fistulizing). One common form of penetrating Crohn’s disease appears as an acute microperforation, often resembling an attack of appendicitis.
- Sachar DB, Andrews HA, Farmer RG et al. Proposed classification of patient subgroups in Crohn’s disease. Gastroenterol Internat 1992;5:151-4.
- Gasché C, Scholmerich J, Brynskov J et al. A simple classification of Crohn’s disease: report of the Working Party for the World Congresses of Gastroenterology, Vienna 1998. Inflamm Bowel Dis 1999;6:8-15.
- Kornbluth A, Sachar DB, Salomon P. Crohn’s Disease (Chapter 101). In: Feldman M, Scharschmidt BF, Sleisenger MH eds., Gastrointestinal and Liver Disease, 6th edition (W.B. Saunders, Philadelphia, 1998), pp.1969-1707.