Inflammatory disorders of GI tract Flashcards
What are some causes of mucosal injury?
GI tract secretions, Ischaemia, Drugs (NSAIDs, antibiotics, steroids), Chemotherapy (e.g., 5-fluorouracil), Immunological (Coeliac disease), Infections (e.g., Helicobacter, Salmonella), Radiation, Trauma, Idiopathic causes, Ulcerative colitis, Crohn’s disease
Includes a range of factors affecting the gastrointestinal tract
What are the manifestations of mucosal injury?
Inflammation, Apoptosis or necrosis, Erosion and ulceration, Hypoplasia and atrophy, Hyperplasia, Metaplasia, Dysplasia +/- neoplasia
These manifestations indicate the severity and type of mucosal damage
What is acute gastritis?
Characterized by acute erosive/haemorrhagic gastritis, ingestion of irritant chemicals, acute H. pylori infection
Often presents with minor symptoms and is seldom seen in biopsies
What is chronic gastritis?
Includes non-atrophic gastritis (chronic H. pylori infection) and atrophic gastritis (autoimmune gastritis)
Can lead to more severe complications if untreated
What are the special forms of chronic gastritis?
Chemical gastritis (bile reflux, NSAIDs), Radiation gastritis, Lymphocytic gastritis, Non-infectious granulomatous gastritis (e.g., Crohn’s disease, sarcoidosis), Eosinophilic gastritis, Other infectious gastritides (non-H. pylori)
These forms have unique etiologies and may require different management strategies
What is coeliac disease?
A hypersensitivity reaction to gluten-rich proteins in wheat, barley, and rye, with a UK prevalence of approximately 1 in 100
Often underdiagnosed; linked to certain HLA class II genes
How is coeliac disease diagnosed?
Combination of histology, serology, and response to a gluten-free diet
It can often be detected in asymptomatic individuals through routine haematology
What are the histological features of coeliac disease?
Variable villous atrophy, chronic inflammation, increased CD8+ T-lymphocytes in epithelium, epithelial damage, crypt hyperplasia
Histological examination is crucial for diagnosis
What are some bacterial infections of the GI tract?
Helicobacter pylori, Shigella, Salmonella, Campylobacter jejuni, Escherichia coli (including O157), Clostridium difficile, Vibrio cholera, Mycobacterium tuberculosis, Atypical mycobacteria (e.g., MAI), Yersinia enterocolitica
These pathogens can cause significant gastrointestinal disturbances
What are some viral infections of the GI tract?
Rotaviruses, Enteric adenoviruses, Herpes viruses (HSV), Cytomegalovirus (CMV), HIV
Viral infections can lead to severe gastrointestinal symptoms, especially in immunocompromised individuals
What are some protozoal infections of the GI tract?
Giardia lamblia, Entamoeba histolytica, Cryptosporidia, Microsporidia
Protozoal infections can cause diarrhea and other gastrointestinal symptoms
What is inflammatory bowel disease (IBD)?
Collective name for two conditions: ulcerative colitis and Crohn’s disease
IBD is characterized by chronic inflammation of the gastrointestinal tract
What are some aetiological factors of inflammatory bowel disease?
Infection, loss of tolerance to normal commensal bacteria, familial/genetic components, environmental factors
Various factors contribute to the development and exacerbation of IBD
What is the role of endoscopic biopsies in IBD?
Exclude other aetiologies, make initial diagnosis, distinguish between Crohn’s and UC, assess response to treatment, assess for complications
Biopsies are crucial for accurate diagnosis and management of IBD
What are the typical features of ulcerative colitis?
Chronic relapsing condition, inflammation confined to mucosa, highest incidence at ages 15-25 and 60-70, typically involves rectum
Symptoms often include rectal bleeding and diarrhea
What are the key characteristics of Crohn’s disease?
Chronic, multifocal, relapsing condition affecting any part of the GI tract, transmural inflammation, peak incidence at ages 20-30 and 60-70
Symptoms vary widely based on the affected area of the GI tract
What is the risk of neoplasia in IBD?
Increased risk in both UC and CD, risk increases with time since diagnosis and severity of disease
Regular surveillance is necessary to manage cancer risk in IBD patients
What are some extra-intestinal conditions associated with coeliac disease?
Endocrine disorders (type I diabetes, thyroid disorders), liver diseases (primary biliary sclerosis), skin conditions (dermatitis herpetiformis), neurological and cardiac issues, increased risk of lymphoma
Coeliac disease can have systemic effects beyond the gastrointestinal tract
What is the difference between ulcerative colitis and Crohn’s disease?
Ulcerative colitis: Colon only, continuous inflammation, broad-based ulcers. Crohn’s disease: Any part of GI tract, patchy inflammation, transmural ulcers
Understanding these differences is crucial for diagnosis and treatment
What can alter the pattern and distribution of inflammation in patients?
Medical therapy (e.g. steroids)
The use of steroids can significantly affect the inflammatory response in patients.
What is used when the distinction between UC and CD is difficult?
IBD-U (IBD unclassified)
This label is applied when it’s challenging to classify the inflammatory bowel disease.
What are common mimics of inflammatory bowel disease?
- Infective colitis (bacterial and parasitic)
- Ischaemic colitis
- Diverticular disease
- Drug-induced colitis
- Radiation colitis
- Neoplasia
These conditions can present similarly to IBD but have different underlying causes.
Where is ischaemic colitis most commonly found?
Region of splenic flexure and descending colon
Ischaemic colitis typically occurs in areas with limited blood supply.
Where is diverticular disease most commonly located?
Sigmoid colon
Diverticular disease often affects the sigmoid region of the colon.
