Crohn's Disease
Pathogenesis
- What is it?
- Crohn's Disease is a chronic inflammatory intestinal disease
- People with CD will experience many flares and remissions throughout their lives once diagnosed
- The role of immunity
- Innate immunity is involved due to defects in the mucous membrane barrier
- Adaptive immunity is involved due to its reliance on helper T cell lymphocytic response and T cells that are regulated by cytokines
- The role of inflammation
- Increased migration of T cells to the site of inflammation alters the extracellular matrix through metalloproteins and adhesion molecules
- How does CD happen?
Resources
- Petagna, L., Antonelli, A., Ganini, C., et al. Pathophysiology of Crohn's disease inflammation and recurrence. Biology Direct 15, 23 (2020). https://doi.org/10.1186/s13062-020-00280-5
- CD is sustained by the inflammatory cells interacting with integrins, adhesion molecules, and chemokines, all causing increased production of inflammatory cytokines and therefore, increased mucosal inflammation
- It can affect any part of the GI tract, but most commonly is seen in the small intestine
- CD commonly affects the entire thickness of the mucosal wall in the bowel
- The immune and inflammatory responses trigger neutrophils to infiltrate the crypts in the small intestine
- Due to all of the neutrophils, abscesses form in the crypts, causing destruction of the crypts
- Granulomas then often form
- The mucosa becomes edematous
- Ghazi, L. J. (2019, July 26). Crohn disease. Medscape. https://emedicine.medscape.com/article/172940-overview#a3
- Ulcers form and get deeper, potentially leading to fistulization
- The ulcers become chronic and CD continues to progress
Incidence/Prevalence
Risk Factors
Diagnostics
Treatments
Clinical Manifestations
- The average age of onset is 30 years
- CD typically peaks twice in individuals who have it: once between ages 20-30 and again around age 50
- CD is most common in North America and Western Europe
- CD is more common in females than males
- CD is also more common in Ashkenazi Jewish people as opposed to non-Jewish people
- 50% of people with CD have involvement in the ileum and the colon
- CD affects 3-20 in every 100,000 people
- Feuerstein, J. D. MD. & Cheifetz, A. S. MD. (2017, June 7). Crohn disease: Epidemiology, diagnosis, and management. Mayo Clinic Proceedings. https://www.mayoclinicproceedings.org/article/S0025-6196(17)30313-0/fulltext
- More than 500,000 Americans are living with CD right now
- Individuals who smoke are twice as likely to develop CD than those who do not smoke
- Thomas, J. (2018, September 24). Crohn's disease: Facts, statistics, and you. Healthline. https://www.healthline.com/health/crohns-disease/facts-statistics-infographic
- Environmental risk factors
- Disturbances in the microbiome of the gut
- GI infections
- NSAIDs
- Antibiotics
- Hormone replacement therapy
- Cigarette smoking, current and former
- Diets high in fat, sugar, oil, and meat
- Genetic risk factors
- More commonly seen in Jewish and North Americans and less common in African Americans and Hispanics
- There is correlation between CD and mutations in the genes on chromosomes 5 and 10
- Cirino, E. (2020, October 2). Crohn's disease: Is it in your gene's? Healthline. https://www.healthline.com/health/crohns-disease/genetic
- The risk of CD is increased with mutations to the ATG16L1, IL23R, IRGM, and NOD2 genes
- If a family member has any IBD, any other family member has a 15-30% chance of developing CD
- Sleep deprivation
- Vitamin D deficiency
- Abnormal Mycobacteria
- Contraceptives
- Past medical history
- The first step in diagnosing CD is taking a look at the medical history of the patient to see if there are any hallmark signs that it could most likely be CD or even be something else
- Blood tests
- Assessing for signs of infection or antibodies through the blood samples
- If there are increased levels of white blood cells or platelets, it could be indicative of inflammation caused by CD
- Antibody tests to distinguish between the likelihood of either CD or UC
- Stool tests
- Assessing for blood in the stool
- Having blood in the stool is indicative of a digestive issue
- Assessing for bacteria or disease-causing organisms in the stool
- If there are abnormal bacteria or organisms found within the stool, this can rule out CD or lead to further testing for it
- Imaging tests
- X-rays, CT scans, and MRI scans
- Each can help to better visualize the GI tract
- Can diagnose complications of CD, such as fistulas or abscesses
- Barium swallow for an upper GI series picture
- Endoscopy
- Used to examine the inside walls of the colon
- Usually looking between the small intestine and colon for the purpose of CD diagnosis
- If granulomas are present, this is often a sign of CD
- Kerr, M. (2020, August 17). Tests for crohn's disease. Healthline. https://www.healthline.com/health/crohns-disease/tests
- Persistant diarrhea
- Rectal bleeding
- Urgent need to have a bowel movement
- Abdominal pain and cramping
- Sensation of incomplete bowel evacuation
- Constipation
- Loss of appetite
- Weight loss
- Low energy and fatigue
- Fissures of the anus
- Fistulas of the anal area
- Visual changes
- Painful and swollen joints
- Fatigue
- Fever
- Crohn's & Colitis Foundation. (n.d.). Signs and symptoms of crohn's disease. https://www.crohnscolitisfoundation.org/what-is-crohns-disease/symptoms
- Medications
- Aminosalicylates to decrease inflammation of the lining of the GI tract
- Sulfasalazine
- Mesalamine
- Olsalazine
- Balsalazide
- Corticosteroids to suppress the immune system
- Prednisone
- Methylprednisolone
- Antibiotics to treat any bacterial infection in the GI tract
- Metronidazole
- Ampicillin
- Ciprofloxacin
- Surgery
- Strictureplasty
- Chronic inflammation of the GI tract can cause narrowing or strictures in the intestines due to scar tissue buildup
- The strictureplasty widens the strictures in the jejunum and ileum without resecting any of the intestine
- Helps to prevent obstructions and blockages
- Protocolectomy and Colectomy
- Colectomy is the removal of the colon
- Protocolectomy is removal of the colon and the rectum
- This will alleviate many symptoms of CD
- Colectomy allows the patient to continue to pass stool through the rectum
- Protocolectomy results in an external pouch for the passing of stool
- Crohn's & Colitis Foundation. (n.d.). Crohn's disease treatment options. https://www.crohnscolitisfoundation.org/What-is-crohns-disease/treatment
- Diet and Nutrition
- Avoid foods that can trigger a flare-up
- Lactose
- Intense spices
- Sugar
- Fat
- Suggested methods for eating
- Eat 4-6 small meals per day
- Stay hydrated by drinking enough water that the urine is pale yellow
- Try not to fry food; boil, steam, or grill instead
- Have patient get to know what foods are right for them, and focus on meals with those items
- Pathak, N. MD (2020, November 10). Crohn's disease treatment: Common medications for treating crohn's. WebMD. https://www.webmd.com/ibd-crohns-disease/crohns-disease/crohns-disease-treatment-common-medications-for-treating-crohns