Crohns Flashcards
Definition
Inflammatory GI disease characterised by granulomatous inflammation anywhere from mouth to anus. Common in terminal ileum and proximal colon. Exacerbations and remissions.
Transmural, asymmetrical, sometimes granulomatous.
Skip lesions.
Bimodal age distribution.
Aetiology
Unknown
Involves immune system dysfunction. Increase TNFa.
Certain gene mutations increase risk.
Gut organism. Eg mycobacterium, pseudomonas.
Triggers eg AB, smoking, infection, fatty diet.
RFs- family history, smoking, female, URTIs, NSAIDs.
Symptoms
Diarrhoea or urgency, bad smell. Abdo pain severe, usually low right. Fatigue. Weight loss. Fever. Malaise Anorexia Vomiting Joint pain.
Differentials
UC Parasite, gastroenteritis, fungal infection. TB IBS Amyloidosis Ischaemic colitis Lymphoma, Colon CA Diverticulitis
Signs
Skip lesions Granuloma Mouth ulcer Fever Anaemia. Abdo tenderness or mass. More frequent and severe abdo pain than UC. Fistulae Aphthoid and deep ulcers- cobblestoning. Granulomas Smoking worsens Perianal abcess, fistulae, skin tag. Anal structures. Clubbing Skin, joint, eye problems.
Management
Nutrition Stop smoking Azathioprine steroid sparing Sulfasalazine not proven in crohns CS, steroid analogues Immunomodulators Immunosuppressants. Methotrexate anti folate (risk leukopenia, infection, pulmonary fibrosis, teratogenic). Metronidazole TNFa inhibitors eg infliximab MAbs Surgery not curative but can help strictures and fistulae, or respect parts repeatedly flare up.
Pathology
Hyperaemia Mucosal oedema Discrete superficial ulcers and deeper ulcers= cobblestone. Thickening bowel wall Fistulae Granuloma.
Investigation
Bloods- anaemia. FBC, UE, LFT, CRP.
CT and MRI- thickening, obstruction, extramural issues, string sign of kantor (incomplete lumen filling due to spasm due to ulcer).
Barium enema or follow through- stricture, fistulae.
Iliocolonoscopy and biopsy.
Stool culture
Complications
SI obstruction Abcess Fistulae eg colovesical, colovaginal, perianal. And strictures. Perforation Colon CA, cholangioCA OP and osteomalacia Fe, folate, B12 deficiency Renal disease eg ureter obstruction by iliocecal disease Abortion, miscarriage, stillbirth.
Anti metabolite eg Methotrexate
Not antifolate in crohns MOA. Maybe inhibit purine metabolism and T activation.
Low dose can combine with other DMARDs, NSAIDs, steroids.
AE-pneumonitis, hepatotoxicity, mucositis, teratogenic.
Monitor all bloods
DDI- binding competition with eg NSAID, phenytoin, tetracyclines, penicillin= increase myelosuppression.
Anti TNF eg infliximab
Dont escalate dose.
Reduce inflammation, angiogenesis.
AE- risk new malignancy if had one previously. Risk serious infections. TB reactivation.
Explanation
- Crohns is a disease that can affect the whole of the digestive system. But it usually is worse in th intestines. It happens when your immune system causes inflammation and damage to the walls of your digestive tract. This affects its function, meaning it cant absorbs things and break down your food as well. This leads to diarrhoea, vomiting and pain.
- it usually comes in phases so you will have a bout of symptoms then they will wear off for a while. In the long term it can cause obstruction because of thickening of the walls, and also it can cause holes to form in the walls. It can also have affects on your joints, skin, and eyes. Also abcesses, CA, renal disease and problems with pregnancy.
- lifestyle diet and stop smoking. Avoid triggers.
- drugs to modulate immune systems damaging affects. Also steroids to prevent inflammation.
