CONDITIONS WHICH CAN MIMIC ULCERATIVE OR CROHN'S COLITIS   - Гастроэнтерология (анг,рус) - Конспект лекций
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Гастроэнтерология (анг,рус)

 CONDITIONS WHICH CAN MIMIC ULCERATIVE OR CROHN'S COLITIS  

    

 

 

Different Endoscopic, and Radiographic Features

CLINICAL

Ulcerative Colitis

Crohn's Disease

Gross blood in stool

Yes

Occasionally

Mucus

Yes

Occasionally

Systemic symptoms

Occasionally

Frequently

Pain

Occasionally

Frequently

Abdominal mass

Rarely

Yes

Significant perineal disease

No

Frequently

Fistulas

No

Yes

Small intestinal obstruction

No

Frequently

Colonic obstruction

Rarely

Frequently

Response to antibiotics

No

Yes

Recurrence after surgery

No

Yes

ANCA-positive

Frequently

Rarely

NOTE: ANCA, antineutrophil cytoplasm antibody

 

 

 

 

 

ENDOSCOPIC

Ulcerative Colitis

Crohn's Disease

Rectal sparing

Rarely

Frequently

Continuous disease

Yes

Occasionally

"Cobblestoning"

No

Yes

Granuloma on biopsy

No

Occasionally

RADIOGRAPHIC

 

 

Small bowel significantly abnormal

No

Yes

Abnormal terminal ileum

Occasionally

Yes

Segmental colitis

No

Yes

Asymmetrical colitis

No

Yes

Stricture

Occasionally

Frequently

 

Investigations 

Blood tests 

            Anaemia results from bleeding or malabsorption of iron, folic acid or vitamin B12.          Serum albumin concentration falls as a consequence of protein-losing enteropathy.

             The ESR is raised in exacerbations or because of abscess.

            Elevation of CRP concentration is helpful in monitoring Crohn's disease activity. 

 

Bacteriology 

            Stool cultures are performed to exclude superimposed enteric infection in patients who present with exacerbations of inflammatory bowel disease. Blood cultures are also advisable in patients with known colitis or Crohn's disease who develop fever. 

 

Endoscopy 

            Sigmoidoscopy with biopsies is a simple and essential investigation in all patients who present with diarrhoea. Rectal sparing, perianal disease and discrete ulcers suggest Crohn's disease rather than ulcerative colitis. 

  Sigmoidoscopic view of moderately active ulcerative colitis. Mucosa is erythematous and friable with contact bleeding. Submucosal blood vessels are no longer visible.

 

            Colonoscopy may show active inflammation with pseudopolyps or a complicating carcinoma. Biopsies are taken to define disease extent.

            In ulcerative colitis the macroscopic and histological abnormalities are confluent and most severe in the distal colon and rectum. Stricture formation does not occur in the absence of a carcinoma.

            In Crohn's colitis the endoscopic abnormalities are patchy, with normal mucosa between the areas of abnormality. Aphthoid or deeper ulcers and strictures are common. 

 

Barium studies 

            In long-standing ulcerative colitis the colon is shortened and loses haustra to become tubular, and pseudopolyps are seen.

 Barium enema showing shortened colon, loss of haustra, pseudopolyps and fine ulceration (arrow).

 

            In Crohn's colitis a range of abnormalities occur. The appearances may be identical to those of ulcerative colitis but skip lesions, strictures and deeper ulcers are characteristic. Reflux into the terminal ileum may show stricture and ulcers. 

 

 Ileocolonic Crohn's disease. Barium enema showing normal rectum and sigmoid colon, typical aphthous ulceration in the descending colon, ulceration (arrow) and lack of haustra in the transverse colon. The ascending colon and caecum are normal and there is typical Crohn's disease affecting the terminal ileum, with coarse ulceration, rigidity and lack of mucosal folds.

 

           

            Contrast studies of the small bowel are normal in ulcerative colitis, but in Crohn's disease affected areas are narrowed and ulcerated; multiple strictures are common. 

 

 Barium follow-through showing terminal ileal Crohn's disease.

 

Plain radiographs 

            A straight abdominal radiograph is essential in the management of patients who present with severe active disease. In colitis dilatation of the colon , mucosal oedema ('thumb-printing') or evidence of perforation may be found. In small bowel Crohn's disease there may be evidence of intestinal obstruction or displacement of bowel loops by a mass. 

 

 Plain abdominal radiograph showing a grossly dilated colon due to severe ulcerative colitis.

 

Radionuclide scans 

            Radio-labelled white cell scans show areas of active inflammation. They are less accurate than other imaging modalities with poor specificity but may be useful in severely ill patients in whom invasive tests are best avoided. 

 MRI  scans are very accurate in delineating pelvic or perineal involvement by Crohn's disease. 

 

Management 

            The key aims are to:

treat acute attacks

prevent relapses

detect carcinoma at an early stage

select patients for surgery.

 Drug treatment of colitis 

            The principles of drug treatment are similar for ulcerative colitis and Crohn's colitis. They are based upon the treatment of active disease and prevention of relapse. 

           

Active colitis. Corticosteroids are the first-line treatment. Active proctosigmoiditis should be managed by steroid foam or liquid retention enemas, from which systemic corticosteroid absorption is clinically insignificant. Patients with very active proctosigmoiditis, those who are unable to retain enemas and those who have active, extensive colitis need oral corticosteroids.

            Prednisolone (30-40 mg/day orally) is given for 2 weeks and then reduced slowly over 8 weeks.

            Severe active colitis can be treated with intravenous methylprednisolone (60 mg daily by infusion).

            Once improvement occurs, the patient is converted to a reducing regimen of oral prednisolone.  Long-term, high-dose therapy must be avoided because of risks of the more severe steroid complications such as metabolic bone disease and infection. 

            Patients who relapse frequently after courses of steroids or who require maintenance steroid therapy may be considered for azathioprine treatment (1.5-2 mg/kg body weight daily). This immunosuppressant drug exerts its maximal effect only after 6-12 weeks, and corticosteroid therapy may have to be continued until this time. Treatment is sometimes complicated by bone marrow suppression, nausea, vomiting, myalgia or acute pancreatitis.

            Some patients respond inadequately to steroids and azathioprine. In these, other immunosuppressive drugs such as methotrexate or immunomodulatory agents have a role. 

            Antidiarrhoeal agents (codeine phosphate, loperamide or diphenoxylate) are sometimes useful but should be avoided in severe active disease. 

 

Maintenance of remission. This is based upon the use of 5-aminosalicylic acid (5-ASA) which acts by modulating intestinal inflammatory activity. High concentrations of 5-ASA are delivered to the colon using the preparations mesalazine or olsalazine and these have replaced sulfasalazine which has a worse side-effect profile.

            Mesalazine is an enteric-coated form in which 5-ASA is slowly released from a cellulose-based or pH-dependent coating.

            Olsalazine comprises two molecules of 5-ASA bound by an azo bond to optimise delivery to the colon.

            5-ASA liquid or foam retention enemas are also available and are as effective as steroid enemas for treating active proctitis. 

 

Medical Management of IBD

Ulcerative Colitis: Active Disease

Mild

Moderate

Severe

Fulminant

5-ASA oral

and/or

enema

5-ASA oral and/or enema

Glucocorticoid enema

Oral glucocorticoid

5-ASA oral and/or enema

Glucocorticoid enema

Oral or IV glucocorticoid

Intravenous glucocorticoid

Intravenous CSA

Ulcerative Colitis: Maintenance Therapy

5-ASA oral and/or enema

6-MP or azathioprine

 

Crohn's Disease: Active Disease

 

Mild-Moderate

 

Severe

Perianal or

Fistulizing Disease

5-ASA oral or enema

5-ASA oral or enema

Metronidazole and/or ciprofloxacin

Metronidazole and/or ciprofloxacin

Metronidazole and/or ciprofloxacin

Azathioprine or 6-MP

Oral glucocorticoids

Oral or IV glucocorticoids

Infliximab

Azathioprine or 6-MP

Azathioprine or 6-MP

Intravenous CSA

Infliximab

Infliximab

 

 

TPN or elemental diet

 

 

Intravenous cyclosporine

 

 

Crohn's Disease: Maintenance Therapy

Inflammatory

Perianal or

Fistulizing Disease

5-ASA oral or enema

Metronidazole and/or ciprofloxacin

Metronidazole and/or ciprofloxacin

Azathioprine or 6-MP

Azathioprine or 6-MP

 

 

NOTE: CSA, cyclosporine; 6-MP, 6-mercaptopurine; TPN, total parenteral nutrition

 

Nutritional therapy 

         Many patients embark upon 'elimination diets' in which specific foods are avoided.

Some colitic patients do improve on a milk-free diet, others respond to avoidance of wheat, the best advice for the majority of patients is to eat a well-balanced, healthy diet and to avoid only those foods which, by experience, are poorly tolerated.                     Nutritional therapy is expensive, is often poorly tolerated and is usually followed by disease relapse on return to a normal diet. 

 

Surgical treatment 

Ulcerative colitis. Up to 60% of patients with extensive ulcerative colitis eventually require surgery.

    

            Surgery involves removal of the entire colon and rectum and cures the patient. The choice of procedure is either panproctocolectomy with ileostomy or proctocolectomy with ileal-anal pouch anastomosis.

 

Crohn's disease.

            Operations are often necessary to deal with fistulae, abscesses and perianal disease, and may also be required to relieve small or large bowel obstruction. 

            Up to 80% of patients eventually need some form of surgical intervention but, unlike ulcerative colitis, surgery does not cure the patients and disease recurrence is the rule.

 

Prognosis 

            Life expectancy in patients with inflammatory bowel disease is now similar to that of the general population.

            Although many patients require surgery and admission to hospital, the majority have an excellent work record and pursue a normal life.

            Clinical recurrence following resectional surgery is present in 50% of all cases at 10 years. 

 

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