Crohn's disease Flashcards
Definition
Inflammatory bowel disease characterised by transmural inflammation of the GIT.
Can affect mouth to anus (most commonly terminal ilium and perianal).
Complications
- Inflammation leads to fibrosis causing bowel obstruction
- Perforation and fistulae.
- Toxic dilation
- Abscess
- Rectal haemorrhage
- Colonic carcinoma
Pathology
Transmural inflammation
- entire intestinal wall
- Neutrophil infiltration in epithelium.
Skip lesions (cobblestone) - ulceration stops abruptly
Affects the ileum + colon (not rectum) most of the time
Granulomas
- from giant cells, found in 50% of cases.
Tissue metaplasia
Epidemiology
- Location
- Peak onset
- Gender
- Ethnicity
- Prevalence
Location
- northern climates, developed countries.
Peak onset= Two peaks.
- 15-40
- 60-80 (smaller peak)
Affects both genders equally.
Ethnicity
- White
- Ashkenazi jews.
Prevalence
- 30-50/ 100000
Risk factors
Strong
- Age: 15-40, 60-80
- White ethnicity.
- Family history: sibling of one affected = 30x risk
Weaker
- Smoking
- Poor fibre diet
- Infective agents
Aetiology
Unknown
- Combination of environmental and genetic predisposition
Intestinal signs and symptoms
Diarrhoea
- non-bloody/ bloody intermittent.
Abdominal pain
- Ilietis= commonly RLQ, peri-umbilical
- Colitis= diffuse.
- Weight loss
- Fever
- Malaise
- Anorexia
- Constipation
Extra intestinal signs
- Erythema nodosum
- Pyoderma gangrenosum
- Uveitis/ Episcleritis/ conjuctivitis
- Large joint arthritis
Examination findings
Abdominal tenderness
Peri-anal abscesses/ lesions
Anal/rectal structures
Extra-intestinal signs
- Eye inflammation
- Clubbling
- Erythema nodosum
- Pyoderma gangrenosum
Investigations
Bloods
- FBC, ESR, CRP, U+E, LFT, blood culture= Anaemia, raised ESR+CRP+ WCC, low albumin.
- Serum Fe3, folate if anaemia present
Stool microscopy/ culture + Clostridium difficile toxin
- Rule out infectious diarrhoea: C.difficile, Salmonella, Shigella, E.coli
Fecal calprotectin.
Sigmoidoscopy + rectal biopsy
- Look for intestinal inflammation and microscopic granuloma
CT abdomen/ Small bowel enema
- Imaging for ilium: strictures, abscess, dilatation.
- Cobble stone ulcers.
- Colonoscopy carried out if enema is equivocal.
Abdominal/ pelvic MRI if CT contrindicated
Management of first presentation/ acute exacerbations
Monotherapy (in first 12 months)
1. Glucocorticosteroid: prednisolone, IV Hydrocorti, Methylpred.
- Budenoside
- Aminosalicylate
Additions: when there are 2+ exacerbations or monotherapy is not toelrated,
1. Azathiprine/ mercaptopurine
- Methotrexate if above not tolerated
Extensive bowel disease treatment
Consider bowel resection
Nutritional therapy
Fecal calprotectin
Biochemical measurement of inflammation in the bowel.
Calprotectin acts as an antimicrobial agent
- When elevated it indicates neutrophils in intestinal mucosa
Budenoside
- Drug type/ Mechanism
- Indication
- Administration
- Side effects
Coriticosteroid
- Glucocorticoid agonist= depresses immunological activity
Indications
- Asthma/ COPD
- First line IBD
Administration
- IBD= orally, 9mg OD
- Can be given rectally
Side effects
- Oral candidiasis
- Headache
- Altered taste
- Altered voice
Azathioprine
- Drug type/ Mechanism
- Indication
- Administration (GI indications)
- Side effects
Immunosuppressant
- Inhibits production of purine, leading to less DNA/RNA produced by white blood cells.
Indications
- First line IBD
- Many AI diseases: RA, SLE, AI Hepatits, MG, MS
Administration
- 2.2.5mg/kG, PO, OD.
Side effects
- Bone marrow suppression
- Increased infections risk
- Leucopenia
- Pancreatitis
- Thrombocytopenia
Infliximab
- Drug type/ Mechanism
- Indication
- Administration
- Side effects
Monoclonal antibody
- TNF-a antagonist
- Reduces production of proinflammatory cytokines
Indications
- Severe IBD, not responding to conventional therapy/ intolerant/ contraindications to previous therapy
- Other AID
Administration
- IV infusion
Side effects
- Infection risk
- Leucopenia
- GI disorders
Management of severe/ non-responsive Crohn’s
- Infliximab/ Adalimumab
- Can be combined with immunosuppressant or used as monotherapy - Ustekinumab/ vedolizumab
- Moderate- severe after previous treatment
Drug types used to treat Crohn’s
Glucocorticosteroids (induce remission)
- Prednisolone
- Methylprednisolone
- IV hydrocorticosone
Budesonide
Immunosuppressants (induce and maintain remission)
- Azathioprine
- Methotrexate
- Mercaptopurine
Monoclonal ab. biological agents (resistant or severe episodes)
- Infliximab
- Adalimumab
- Ustekinumab
- Vedolizumab
