GI - Crohn's Disease and Coeliac Disease Flashcards
General definition of Crohn’s
Form of IBD- commonly affects terminal ileum and colon but can present anywhere from mouth to anus
What is the pathology of Crohn’s?
- Cause is unknown but there is a strong genetic susceptibility
- Inflammation occurs in all layers, down to serosa (explains why pts are prone to strictures, fistula and adhesions)
Give 5 features of Crohn’s presentation
- Sometimes are non-specific: wt loss and lethargy
- Diarrhea: most prominent symptoms in adults. Crohn’s colitis can cause diarrhoea but this is more common in UC
- Abdo pain: most prominent symptom in kids
- Perianal disease: skin targs/ulcers
- Extra-intestinal features: more common in pts with colitis or perianal disease
What Ix would you perform for a Crohn’s pt?
Bloods
- CRP: correlates well with disease activity
- FBC: anaemia
- LFT, U&Es, TFTs, iron studies, B12/folate
Endoscopy
- Colonoscpy: Ix of choice (features of Crohn’s include deep ulcers and skip lesions)
- faecal cal protection
Imaging -Small bowel enema with imaging
- High sensitivity and specificity for examining terminal ileum
- strictures: ‘Kantor’s string sign’
- proximal bowel dilation
- ‘rose thorn’ ulcers
- fistulae
What general advice should you give with regards to Crohn’s Mx?
-Pt strongly advised to stop smoking
How do you induce remission in Crohn’s?
- 1st line: Glucocorticoids (oral, topical or IV)
- 2nd line: 5-ASA drugs (eg mesalazine)
- Azathioprine/Mercaptopurine: can be used as add-on to induce remission but is not used as mono therapy (Methotrexate can be alternative to Azathioprine)
- 3rd line: Infliximab (TNF alpha blocker): useful in refractory disease and fistulating Crohn’s (pts typically continue on azathioprine or methotrexate while on this)
Extras:
- Enteral feeding with elemental diet in addition to other measures can be helpful - bowel rest
- Metronidazole: often used for isolated peri-anal disease
How do you maintain remission in Crohn’s?
- Stop smoking (makes Crohn’s better but may help in UC)
- 1st line: Azathioprine/Mercaptopurine
- 2nd line: Methotrexate
- 3rd line: 5-ASA drugs (eg mesalazine/sulfasalazine) considered if pt has had previous surgery
What surgical interventions can be performed for a Crohn’s pt?
- Commonest disease pattern in Crohn’s: structuring terminal ileal disease - often culminates in ileal resection
- Other procedures: segmental small bowel rejections and stricturoplasty
- Recurrence of disease is very high: no role for restorative procedures (ileoanal pouch)
- Fistulation is common: may require surgery
What are complications of Crohn’s disease?
- Fistulation, obstruction, bowel perforation
- Small bowel cancer
- colorectal cancer (less than the risk associated with UC)
- Osteoporosis
Coeliac disease: Definition and associated conditions
- Disease caused by sensitivity to gliadin portion of gluten. Repeated exposure leads to villous atrophy, which causes malabsorption
- Associated conditions: dermatitis herpetiformis (vesicular, pruritic skin eruption), auto-immune disorders (type 1 DM and auto-immune hepatitis/thyroiditis) and enteropathy-associated T cell lymphoma (EATL)*
*Any hints to malignancy in context of coeliac disease question should prompt EATLs consideration
Coeliac disease: Ix - how is Dx mage and what other investigations should you do?
-Dx: combination of immunological and jejunal biopsy (villous atrophy and immunology reverses on gluten free diet)
Immunology
- 1st line: Tissue trans glutamine seems (TTG) antibodies (IgA)
- Others: endomyseal antibody (IgA), anti-casein abs (found in some pts)
Duodenal biopsy
- Villous atrophy, crypt hyperplasia
- increase in intraepithelial lymphocytes, laminar propria infiltration with lymphocytes
*if pt comes to doctor and says they are symptom free after cutting gluten out - must make them go back on gluten for 6wks in order to make Dx with Ix (sad face)
What is the Mx for coeliac disease?
- Gluten free diet! (Cut out: wheat, barley, beer, rye, oats) and eat rice, potatoes and corn
- Pts often have degree of functional hyposplenism: offer pneumococcal vaccine and also offer flu vaccine on individual basis
