Inflammatory bowel disease Flashcards
What are the 2 types of IBD’s a patient could have?
- Crohn’s
- Ulcerative colitis
What is Crohn’s disease?
Chronic granulomatous/patchy inflammatory disease that can affect any part of the gastrointestinal tract. Damage and inflammation extends beyond the submucosal layer through the entire depth of the intestinal wall (transmural).
CROHN’S ⇒ transmural, skip lesions, smoking is RF, cobblestone appearance, non-caseating granulomas, increased goblet cells, small bowel enema shows Kantor’s string sign and rose thorn ulcers.
What causes crohn’s disease?
- Disorder of unknown aetiology caused by transmural granulomatous inflammation of the GI tract
- Thought to be caused by an abnormal Th1 cellular response
- As it is Th1-mediated, causes more severe inflammatory response which can penetrate all the way through the gut and affect any point of GI tract from mouth to anus.
- Most commonly/ severely affects terminal ileum (70%).
Describe the epidemiology of crohn’s disease
M=F, 2 age peaks → 15-40 yrs (main peak) and 60-80 yrs
- UK annual incidence: 5-8/100,000
- UK prevalence: 50-80/100,000
- Affects any age but peaks in teens, 20s and 40s
What are the risk factors for crohn’s disease?
white ethnicity, FH of CD, age peaks, smoking
What are the presenting symptoms of crohn’s?
- Crampy abdominal pain (due to inflammation, fibrosis or bowel obstruction)- RLQ Abdominal Pain → may be relieved by defecation
- Diarrhoea (usually non-bloody)
- Fever, malaise
- Symptoms of complications – eye disease (uveitis), joint disease (seronegative arthritis), skin disease (erythema nodosum), anaemia
- Lethargy
- Transmural; malabsorbtion= weight loss and anaemia
What signs of crohn’s can be found on physical examination?
- Weight loss
- Clubbing
- Signs of anaemia
- Aphthous ulcers in mouth
- Perianal disease: skin tags, fistulae and abscesses
- Skin Lesions → erythema nodosum (erythema on shins) and pyoderma gangrenosum (ulcers on legs)
- Arthropathy (Joint Pain)
- Ocular Symptoms → anterior uveitis (painful red eye with loss of vision and photophobia), episcleritis (painless red eye)
What investigations are used to diagnose/ monitor crohn’s?
- Colonoscopy + Biopsy → deep ulcers, skip lesions, cobblestone appearance
- Histology → transmural inflammation with non-caseating granulomas
- Barium Enema → Kantor’s string sign and ‘rose thorn’ ulcers
- Faecal Calprotectin → raised (can help distinguish IBS and IBD)
- FBC → anaemia due to chronic inflammation, chronic blood loss, iron malabsorption or malabsorption of B12/folate
- Increased CRP & ESR → inflammatory markers correlate closely with activity of CD
- Stool MC&S → exclude infections
- Serum vitamin B12 (absorbed in terminal ileum) & Folate → reduced due to malabsorption
- Plain AXR or CT Abdomen
How is Crohn’s managed?
- Induce Remission → Prednisolone or Budesonide (Corticosteroids)
- Maintain Remission → 1st line- Azathioprine/Mercaptopurie or 2nd line - Methotrexate (Immunomodulators)
- Azathioprine ⇒ may cause myelosuppression, reducing WCC.
*Should be monitored with FBC.
* This risk is significantly increased due to interactions with several drugs.
* Of those listed here, allopurinol is most likely to interact with azathioprine and cause leukopenia
- Smoking Cessation - Biologics → Infliximab
(Can’t do curative surgery due to skip lesions, unlike UC which is continuous)
What complications may arise from crohn’s?
small bowel obstruction (stricture and fistula formation), anaemia (terminal ileum is where B12 is absorbed) , malignancy, kidney stones, gallstones (Terminal ileitis affects the absorption of bile salts, increasing the risk of gallstone formation), perianal fistula (fistulotomy or draining seton, MRI to visualise) and abscess (incision + drainage)
What is ulcerative colitis?
Chronic relapsing and remitting inflammatory disease affecting the large bowel. Form ulcers along the inner-surface/lumen of the LI. Ulcers are spots where the tissue has eroded away and left behind open sored/breaks in the membrane.
- Starts in rectum and spreads proximally, always continuous
UC ⇒ mucosa and submucosa only, continuous, smoking is protective, crypt abscesses, decreased goblet cells, pseudo polyps, barium enema shows lead pipe appearance.
Summarise the prognosis for patients with Crohn’s disease
It is a chronic relapsing condition
2/3 of patients will require surgery at some stage
2/3 of these patients require more than 1 operation
What causes ulcerative colitis?
UNKNOWN
1. Possible genetic susceptibility (chr 12, 16)
2. Other factors involved: immune response to bacterial or self-antigens, environmental factors, altered neutrophil function and abnormality in epithelial cell integrity
3. Considered to be Th2 mediated – IL-13 is key
4. Positive family history - 15% of patients
5. Associations:
Elevated serum pANCA
Primary sclerosing cholangitis (70% of patients with PSC have UC)
Summarise the epidemiology of ulcerative colitis
- Higher prevalence in:
- Ashkenazi jews
- Caucasians - Uncommon before the age of 10 yrs
- Peak onset: 20-40 yrs
- Equal sex ratio up to the age of 40 yrs (higher in males from then on)
what are the presenting symptoms of ulcerative colitis
- Bloody or mucous diarrhoea (stool frequency depends on severity of disease) → episodic or chronic
- LLQ Pain
- Tenesmus and urgency→ suggestive of proctitis
- Crampy abdominal pain before passing stool
- Weight loss
- Fever
- Extra-GI manifestations (e.g. uveitis, scleritis, erythema nodosum, pyoderma gangrenosum)
