Dietary Sensitivity and Chronic Inflammatory Enteropathies Flashcards
Which dietary sensitivities are non-immunologically mediated?
Repeatable - food intolerance
Non-tolerance - dietary indiscretion, intoxication, contamination (poisoning)
Which dietary sensitivities are immunologically mediated?
Food allergy (hypersensitivity) - repeatable, often suspected but rarely proven
Describe adverse food reactions (food allergies).
Immunologically mediated, usually to a protein
Oral tolerance = complex series of signalling and processing events resulting in ‘tolerance’ of foreign antigens - failure of this leads to AFR
Most commonly manifest as delayed hypersensitivity (type 4)
Commonly affects dermatological and/or GI systems
What are the clinical signs of a food allergy?
Pruritis/erythema - most common, usually seen without GI signs
GI - vomiting/diarrhoea, non-specific so need to differentiate from other causes
Systemic - anaphylaxis
How do we diagnose and manage a food allergy?
Exclusion/limitation - choose specific diet with novel/hydrolysed proteins, limit to only specific diet
Challenge and rescue - put back on original diet to see if problems recur
Provocation and rescue - add in one allergen at a time to see which causes recurrence
Maintenance
Define chronic inflammatory enteropathies (CIE).
Group of diseases with chronic GI inflammation
Symptoms = vomiting, diarrhoea, dysorexia, weight loss
>3 weeks duration
What other diseases must be excluded before a diagnosis of CIE can be made?
Exocrine pancreatic insufficiency
Local abdominal inflammation (pancreatic, renal, hepatic)
Metabolic e.g. portosystemic shunts, hypoadrenocorticism, hyperthyroidism
How can we diagnose chronic inflammatory enteropathies?
Exclusion of other causes of symptoms
Lab tests e.g. faecal analysis, bloods
Imaging e.g. abdo ultrasound
If normal - diagnosis of CIE
Biopsies indicating BOTH inflammation and architectural changes e.g. villi atrophy
What are some causes of chronic inflammatory enteropathies?
Food responsive disease - diet trial
Antibiotic responsive disease - select breeds only
Idiopathic disease - endoscopy
Describe idiopathic CIEs.
Previously termed IBD
Immunological disorder
Loss of tolerance to mucosal flora
Describe laparotomy biopsies.
Enables multiple full-thickness biopsies
Enables full exploration of other organs
Surgical risk of dehiscence
Describe endoscopy biopsies.
Minimally invasive
Small mucosal biopsies
May not reflect jejunal disease
What are the consequences/complications of CIEs?
Dehydration
Protein losing enteropathy - hypoalbuminaemia (leads to pleural/peritoneal effusions, oedema, thromboembolic events)
Hypocobalaminaemia
GI haemorrhage +/- anaemia
GI perforation (rare)
How can we supportively manage CIEs?
IVFT and electrolyte balance
Nutrition - exclusion diet, tube feeding in severely affected patients, anti-emetics/appetite stimulants
What medications can we use to manage CIEs?
Immunosuppression - prednisolone +/- adjuncts
+/- fenbendazole
+/- metronidazole
+/- vitamin B12
+/- anti-platelet drugs
