Crohn`s disease and ulcerative colitis are distinct clinical entities collectively referred to as "inflammatory bowel disease" (IBD). Crohn`s disease is an immunologically mediated inflammatory gastrointestinal condition, with pathology involving the entire thickness of the bowel wall.
How common is Crohn`s disease?
Crohn`s disease is most commonly seen in North America, Northern Europe, and New Zealand with the onset occurring most frequently between ages 15 and 30 and 40 and 60. Experts estimate that more than three-quarters of a million people in the U.S. have Crohn’s disease. It affects approximately 6 to 8 million people globally.
What are the causes of Crohn`s disease?
The exact cause of Crohn`s disease is unknown. Substantial evidence suggests that the condition may result from an inappropriate immune response to environmental antigens like drugs, toxins, infections, or intestinal microbes in a genetically susceptible host. Large-scale genome studies have identified over 200 IBD-associated genes and more than 71 Crohn disease–susceptibility loci.
Genetic variants are associated with certain Crohn disease phenotypes. For example, NOD2/CARD15 mutations have been detected in patients with Crohn disease presenting with ileal involvement and increased severity at a younger age. These individuals often require surgical intervention.
What is the pathophysiology of Crohn`s disease?
The excessive immune response arises from innate and acquired mechanisms involving intestinal macrophages, neutrophils, and helper T-cells (Th), promoting proinflammatory mediators like tumour necrosis factor-α (TNF-α). Th1 and Th17 are crucial mediators in the Crohn disease inflammatory cascade. Colonic Crohn lesions were found to have high levels of cytokines like interferon-γ and interleukins (ILs) 2, 12, and 18. (https://www.ncbi.nlm.nih.gov/books/NBK436021/)
What are the types of Crohn`s disease?
Crohn`s disease can involve any part of the digestive tract between mouth and anus. Inflammation is most commonly seen in the small and/or large intestines. Types of Crohn’s disease include:
What are the symptoms of Crohn`s disease?
Symptoms of Crohn`s disease may come on gradually or suddenly and they may be mild to severe.
Symptoms of other systems involvement include:
Complications of Crohn`s disease include abscesses, anal fissures, fistulas, bowel obstruction, colon cancer, blood clots, malnutrition and anaemia. (https://my.clevelandclinic.org/health/diseases/9357-crohns-disease)
How is Crohn`s disease diagnosed?
A thorough abdominal assessment will be part of physical examination, along with vital signs assessment which may reveal fever, tachycardia, and hypotension. Your physician may also examine the skin, musculoskeletal, renal and neurological systems to find extraintestinal manifestations of Crohn`s disease.
Laboratory tests include:
C-reactive protein (CRP) or erythrocyte sedimentary rate elevation may reflect inflammation severity.
Imaging
Ultrasound does not pose a radiation risk and is widely available, though the image may not have good resolution. Features that may be appreciated using this modality include fistulae, free intraperitoneal fluid, abscess formation, and increased superior mesenteric artery flow. The superior mesenteric artery often has increased flow volume during active disease that may be documented by Doppler ultrasound.
How is Crohn`s disease treated?
Currently, there is no cure for Crohn`s disease and treatment options are aimed at symptom relief. As, symptoms vary across the individuals, there are multiple options to choose from:
Anti-inflammatory medication
Immune system suppressors
Biologics
Janus kinase inhibitors
Taken orally, these newer medicines help reduce inflammation by targeting parts of the immune system that cause inflammation in the intestines.
Antibiotics
Antibiotics can reduce the amount of drainage from fistulas and abscesses and sometimes heal them in people with Crohn's disease. Some researchers also think that antibiotics help reduce harmful bacteria that may be causing inflammation in the intestine. Commonly prescribed antibiotics include ciprofloxacin (Cipro) and metronidazole (Flagyl).
In addition to controlling inflammation, some medications like anti-diarrheal, pain relievers and supplemental vitamins may provide symptomatic relief.
Surgery
If diet and lifestyle changes, medicines, or other treatments don't relieve symptoms, a healthcare professional may recommend surgery.
During surgery, the surgeon removes a damaged portion of your digestive tract and then reconnects the healthy sections. Surgery also may be used to close fistulas and drain abscesses. The best approach is to follow surgery with medicine to reduce the risk of recurrence. (https://www.mayoclinic.org/diseases-conditions/crohns-disease/diagnosis-treatment/drc-20353309)