GI: Inflammatory Bowel Disease Flashcards
What are the two major forms of IBD?
- Crohn’s Disease
- Ulcerative colitis
What environmental factors are associated with the development of IBD?
- Smoking
- NSAID ingestion
- Hygeine
- Nutrition
What is thought to be the primary cause of IBDs?
Inappropriate immune response against the gut flora in a genetically susceptible individual
How much does smoking increase the risk of developing IBD?
3-4x the risk
List the mediactions used in IBD managament
5ASAs (Aminosalicyclates)
Corticosteroids
Immunomodulators
Biologics
Other - antibiotics
What is ulcerative colitis?
Relapsing/Remitting inflammaotyr disorder of the colonic mucosa. It may affect the rectum, or extend to involve part of the colon, or the entire colon. It never spreads proximal to the ileocaecal valve (except for backwash ileitis)
What are the main sites of crohns?
Most commonly targets distal ileum/proximal colon
Affects small bowel so think malabsorption
What are the main sites the ulcerative colitis occurs?
- Proctitis - rectum
- Left-sided colitis
- Pancolitis - whole colon
What are the pathological features of UC?
- Hyperaemic/Haemorrhagic colonic mucosa +/-pseudopolyps
- Thin wall appearance (red mucosa, bleeds early)
- Superficial ulcers
- Punctate ulceration (crypt absess)- extends deep into lamina propria
No inflammation occurs beyond submucosa
What distinguishes UC from Crohn’s Pathologically?
- Crohn’s is transmural, whereas UC is primarily mucosal
- Granulomas are often present in Crohns
What are the pathological features of Crohn’s Disease?
- Granulomas
- Fissuring ulceration
- Focal/Patchy mucosal involvement
- Neuromuscular hypertrophy
Which IBD does skip lesions occur in?
Crohn’s - areas of unaffected bowel between areas of active disease
Which IBD does backwash ileitis occur in?
UC - usually in pancolitis
What is the difference in terms of the affected bowel between Crohn’s and UC?
- Crohn’s - Thickened wall + strictures/narrowed lumen
- UC - Ulcerated wall with dilated lumen
Which IBD produces granulomas?
Crohn’s
Which type of IBD tends to fistulate more commonly?
Crohn’s
Which type of IBD are more at risk of cancer?
UC
Why does the bowel wall thicken in Crohn’s?
Due to oedema and fibrosis
Typical presentation uclerative colitis
Could be one of:
- Persistent diarrhoea
-
Chronic type (relapses and remission)
- Initial attack of moderate severity followed by recurrent exacerbations
- Patient can look wasted from severe diarrhoea and anaemia from chronic blood loss
-
Severe fulminant colitis
- Bowel movements >10hours/24hours
- Fever, tachycardia, continuous bleeding, anaemia, reduced albumin
- Abdominal distension (toxic megacolon)
What are symptoms of UC?
Episodic attacks (typically follows a relapsing remitting course)
- Diarrhoea (episode/chronic) +/- blood/mucus
- Urgency +/- tenesmus
- Crampy abdominal discomfort
- Increased frequency
- Systemic features in attacks - fever, malaise, anorexia, weight loss
What signs may be present in someone with UC?
May be none. If presenting during an attack:
- Fever
- Tachycardia
- Tender, distended abdomen
Extraintestinal signs (chronic)
What extraintestinal signs may be seen in IBD?
-
Skin
- Clubbing
- Erythema nodosum
- Pyoderma gangrenosum
-
Eyes
- Conjunctivitis
- Uveitis/Episcleritis/Iritis
-
Joints
- Large joint arthritis (pauciarticular, asymmetric)
- Sacroiliitis
- Ankylosing spondylitis/inflammatory back pain
- Osteoporosis
-
HPB
- PSC and cholangiocarcinoma (esp in UC)
- Gall stones (esp CD)
- Fatty liver
-
Other
- Nutritional defects
- Venous thrombosis
- Amyloidosis
What is the following seen in?
Pyoderma gangrenosum
- Idiopathic: 25–50% of cases
- Inflammatory bowel disease: up to 50% of cases
- Rheumatological disease
- Paraproteinaemia
- Haematological malignancy
What is the following?
Erythema nosodum - A skin disorder of acute onset with eruption of red, tender nodules and plaques, predominantly over the lower extremities, especially the extensor surfaces. It is a form of panniculitis
What is the mechanism behind erythema nodosum?
In theory, immune complexes form after exposure to an antigen and are deposited in venules around areas of subcutaneous fat and connective tissue. The subsequent inflammation causes the lesions.
Why the lesions appear so frequently on the shins has not been explained - suggested that a combination of a relatively meagre arterial supply combined with gravitational effects on venous system gravitational favour deposition in that area
What are causes of the following?
- Inflammatory bowel disease
- Infections – streptococcal, tuberculosis, URTIs, yersiniosis
- Sarcoidosis
- Rheumatological disorders
- Drug reactions – usually sulfonamides and the oral contraceptive pill
- Malignancies
- Pregnancy
What is the following?
Clubbing
What are causes of the following?
- Cyanotic heart disease/Crohn’s
-
Lung disease - ABCDEF
- Abscess
- Bronchiectasis
- CF
- DON’T SAY COPD
- Empyema
- Fibrosis
- Ulcerative colitis
- Biliary cirrhosis
- Birth defect
- Infective endocarditis
- Neoplasm
- GI malabsorption syndrome (coeliac)
What is the following?
Episcleritis - benign, self-limiting inflammatory disease affecting part of the eye called the episclera.
What is the following?
Scleritis - a serious inflammatory disease that affects the white outer coating of the eye, known as the sclera
What are signs of anterior uveitis?
- Circumcorneal redness - ciliary flush
- Keratic precipitates on corneal epithelium
- Cells/flare in anterior chamber
- Miosis - due to sphincter spasm
- Hypopyon
- Posterior/Peripheral anterior Synechaie/Festooned pupil
- Iris atrophy
- Fibrinous membrane in the pupillary
What are symptoms of crohn’s disease?
Symptoms depend on region of bowel involved
-
SI
- Abdominal pain
- Weight loss
-
Terminal ileum
- COMMONEST AT ILEO-CAECAL VALVE
- Presents as acute abdo with RIF pain mimicking appendicitis
-
Colonic
- Diarrhoea, bleeding and pain related to defecation (although doesnt usually contain blood - thats more UC)
-
Perianal
- Anal tags
- Fissures
- Fistulas
- Abscess
OTHER:
- Failure to thrive
- Fatigue
- Fever
- Malaise
- Anorexia
What are signs of crohn’s disease?
- Abdominal tenderness/mass esp RIF
- Perianal abscess/fistulae/skin tags
- Anal strictures
- Apthous ulcers
- Systemic features of IBD
Potential acute presentations of crohns
- Acute abdomen
- Intestinal obstruction
- Peritonitis (due to perforation)
- Fulminate colitis (less common than UC)
Complications of crohn’s
-
Fistulae
- Most commonly fistulae come from anus to peri-anal region and then produce pus
- Hence never do ileal pouch in crohns
- Seton suture
-
Strictures
- Can cause obstructions
- Abscessess
-
Malabsorption
- Fat causing renal and gallstones
- B12
- Vit D
- Protein
What is the following?
Apthous ulcer - A painful open lesion anywhere within the oral cavity.
What are causes of the following?
- Trauma
- Stress
- Toothpaste
- Iron deficiency/Folate deficiency/Vitamin B12 deficiency
- Food hypersensitivity
- Humoural/immunological
- Inflammatory bowel disease
- Behçet’s disease
- SLE
- HIV/AIDS
- Nicorandil
How would you approach investigating someone who you suspected had UC?
- Bedside - NEWS score
-
Bloods - FBC, ESR, CRP, U+E’s, LFTs, Blood culture
- Raised WCC
- Reduced Hb
- Raised platelets
- LFTs: hypoalbuminaemia (and LFTs can become derranged in severe attack because large ammount of inflammation affects coag cascade)
- pANCA psoive in 70%
-
Imaging
- AXR
- Flexible sigmoidoscopy - acute attack
- Colonoscopy once controlled
-
Other -
- stool culture,
- faecal calprotectin (+ve in inflammatory bowel but not IBS)
- biopsy
What might you find on stool studies in someone with UC?
- Negative culture
- WBC present
- Elevated faecal calprotectin
What might you see on FBC in someone with UC?
- Variable degree of anaemia
- Leukocytosis
- Thrombocytosis
What might you see on LFTs in someone with UC?
Looking for features of PSC:
- Elevated ALP
- Elevated Bilirubin
- Elevated AST/ALT
- Hypoalbuminaemia
What might you see on U+E’s in someone with UC?
- Hypokalaemia metabolic acidosis
- Hypernatraemia