Crohn's Disease Flashcards
What is inflammatory bowel disease (IBD)?
It is defined as chronic, relapsing-remitting conditions in which there is inflammation of the gastrointestinal tract
What are the two inflammatory bowel disease disorders?
Ulcerative colitis (UC)
Crohn’s disease
What is Crohn’s disease?
It is an intermittent inflammatory bowel disease that most commonly affects the terminal ileum and colon; however, it can affect the entire gastrointestinal tract
What is the aetiology of Crohn’s disease?
The underlying aetiology remains unclear
However, there is evidence that the combination of an altered intestinal microbiota and compromised colonic epithelial integrity, results in the inappropriate exposure of non-sterile intestinal contents to the underlying immunological tissue – resulting in inflammation
What are the six risk factors of Crohn’s disease?
Young Age < 30 Years Old
Ashkenazi Jewish Descent
IBD Family History
HLA-B27 Positive
Gastrointestinal Infection
Smoking
What gene is associated with Crohn’s disease?
NOD-2
What are the five clinical features of Crohn’s disease?
Non-Bloody Diarrhoea
Right Iliac Fossa Pain/Mass
Perianal Disease
Mouth Ulcerations
Weight Loss
What is the most common clinical feature of Crohn’s disease in children?
Abdominal pain
What are the nine extra-intestinal manifestation of Crohn’s disease?
Gallstones
Oxalate Renal Calculi
Colorectal Cancer
Arthritis
Osteoporosis
Erythema Nodosum
Pyoderma Gangrenosum
Uveitis
Episcleritis
What pneumonic is used to remember the extra-intestinal manifestations of Crohn’s disease?
A PIE SAC
Aphthous Ulcers
Pyoderma Gangrenosum
Iritis
Erythema Nodosum
Sclerosing Cholangitis
Arthritis
Clubbing
What are the three most common extra-intestinal manifestations of Crohn’s disease?
Gallstones
Oxalate Renal Calculi
Episcleritis
What four investigations are used to diagnose Crohn’s disease?
Blood Tests
Stool Tests
Endoscopy + Biopsy
Abdominal X-Ray (AXR)
What are the five blood test results that indicate Crohn’s disease?
Decreased RBC Levels
Increased WCC Levels
Increased CRP Levels
Decreased Albumin Levels
Decreased Vitamin B12 Levels
What are the two stool tests used to diagnose Crohn’s disease?
Faecal Calprotectin
Stool Culture
What is faecal calprotectin?
It is an inflammatory marker, which is released during colitis
What faecal calprotectin result indicates Crohn’s disease?
There are elevated levels of this inflammatory marker present in stool cultures – usually > 200ug/g
How is faecal calprotectin used to investigate Crohn’s disease?
This stool test is useful for distinguishing between inflammatory bowel syndrome and inflammatory bowel disease
How are stool cultures used to investigate Crohn’s disease?
They are used to exclude gastrointestinal infections
What three gastrointestinal infections present similarly to Crohn’s disease, and are therefore important to exclude?
Salmonella
E.coli
Campylobacter
What is the gold standard investigation used to diagnose Crohn’s disease?
Endoscopy with biopsy
What are the four macroscopic features of Crohn’s disease on endoscopy?
Skip Lesions of Inflamed Mucosa
Cobble-Stone Appearance
Erythematous Mucosa
Transmural Inflammation
What is transmural inflammation?
It is defined as the infiltration of inflammatory cells to all layers - from mucosa to serosa
What are the two microscopic features of Crohn’s disease on endoscopy?
Increased Goblet Cell Abundance
Granuloma Formation
What are the four features of Crohn’s disease on abdominal x-ray?
Proximal Bowel Dilation
Kantor’s String Sign
Rose Thorn Ulcers
Fistulae
What is Kantor’s string sign?
It is a severe narrowing of bowel loop
What is rose thorn ulcers?
They are sections of stenosed terminal ileum, which are filled with barium enema
How do we conservatively manage Crohn’s disease?
We advise patients about smoking cessation
What is the first line management option for the induction of remission in Crohn’s disease?
Corticosteroids
Name two corticosteroids are used to manage Crohn’s disease
Oral prednisolone
IV hydrocortisone
What is the second line management option for the induction of remission in Crohn’s disease?
Aminosalicylates (5-ASA)
Name an aminosalicylate (5-ASA) used to manage Crohn’s disease
Mesalazine
What is the third line management option for the induction of remission in Crohn’s disease?
Thiopurines
Name two thiopurines used to manage Crohn’s disease
Azathioprine
Mercaptopurine
What are the two fourth line management options for the induction of remission in Crohn’s disease?
Biologics
Immunosuppressants
What are the four side effects of azathioprine?
Bone marrow depression
Nausea & vomiting
Pancreatitis
Increased non-melanoma skin cancer
What blood test should be conducted prior to administration of azathioprine? Why?
Thiopurine Methyltransferase (TPMT) Activity
When very low/absent, azathipurine should not be administered. When decreased, hower not deficient, it should be commenced at a lower dose
What blood test should be conducted to monitor complication development of azathioprine? Why?
Full blood count
This is to monitor development of bone marrow depression
Name two biologics used to manage Crohn’s disease
Infliximab
Adalimumab
What is the mechanism of action of infliximab?
Anti-TNFa
What is the mechanism of action of adalimumab?
Anti-TNFa
Name an immunosuppressant used to manage Crohn’s disease
Methotrexate
What should patients be aware of when taking methotrexate?
They require effective contraception during and for at least 6 months after treatment
This applies to both men and women
What is the first line management option for remission maintenance in Crohn’s disease?
Thiopurines
What is the second line management option for remission maintenance in Crohn’s disease?
Immunosuppressants
What is the third line management option for remission maintenance in Crohn’s disease?
Biologics
What is a surgical management option of Crohn’s disease?
Proctectomy
When is proctectomy used to manage Crohn’s disease?
It is used to manage severe rectal Crohn’s disease, in which rectal complications such as haemorrhae and fistulae have developed
What are the eight complications of Crohn’s disease?
Anal fissure
Perianal Fistulae
Perianal Abscess
Bowel Obstruction
Gallstones
Malnutrition
Vitamin B12 deficiency anaemia
Small Bowel Cancer
Colorectal Cancer
In Chron’s disease, what is th most likely cause of bleeding post-defecation?
Anal fissure
What is the management option used to manage perianal abscesses in Crohn’s disease?
Incision and drainage
What is the gold standard investigation used to investigate perianal fistulae in Chron’s disease?
MRI Pelvis
What is the management option for simple perinal fistulae in Crohn’s disease?
Oral Metronidazole
What is the management option for complex perinal fistulae in Crohn’s disease?
Draining Seton
What is a seton?
It is a piece of surgical thread that is run through the fistula to allow continuous drainage while the fistula is healing
This ensures that the fistula doesn’t heal containing pus within, which would result in further abscess formation
What pneumonic is used to remember the key features of Crohn’s disease?
crowns NESTS
No blood or mucus
Entire GI tract
Skip lesions
Terminal ileum/Transmural inflammation
Smoking risk factor
How do we remember that smoking is a risk factor of Crohn’s disease?
Smoking sets a NEST on fire
What pharmacological management option is only used to treat Crohn’s disease and not ulcerative colitis?
Methotrexate
