Food Allergy Flashcards
Define food allergy in children.
Immune mediated hypersensitivity reaction to food proteins.
Explain the aetiology/risk factors of food allergy.
Associated with parental atopy and atopic eczema, allergy, allergic rhinitis.
Summarise the epidemiology of food allergies in children.
6-8% of children
What are the eight most common causes of food allergy?
- Cow’s milk
- Peanuts
- Sesame
- Kiwi
- Eggs
- Wheat
- Fish
- Soybean
- Shellfish
- Nuts
What are the signs and symptoms of food allergy?
Immediate IgE (1h):
- Skin – Flush, itch, urticarial, angioedema
- Resp - Wheeze, angioedema, cough, bronchospasm
- CVS - Tachycardia and hypotension
- GI - Vomiting, diahrrea, abdominal pain
Pathophysiology: exposure to food in a sensitized individual leads to mass degranulation of PG/LKT from Mast cells, activated by IgE cross binding.
Mixed IgE and Non IgE (2-12h)
- Skin - Atopic eczema
- GI - Eosinophilic oesophagitis (leading to reflux, food aversion, dysphagia) proctolitis (bloody stools in otherwise well child)
Delayed non IgE (12+h)
- GI - Food protein induced enterocolitis, FPIES – presents with vomiting and possibly diahrrea, shock and metabolic acidosis. Failure to thrive, constipation.
- Pathology - Food protein taken up by APCs, presented to T cells. Th2 interact with B cells and produce allergic cytokines leading to inflammation.
What is the management for food allergy?
Avoidance: Once confirmed, dietitian input is key. Advice on eating out, food labels etc.
Emergency plan: In IgE mediated, training on how to assess severity of reaction. Wearing MedicAlert bracelet. Epipen is indicated in children with proven cardiorespiratory symptoms as a result of contact with allergen. Often indicated in peanut or tree nut allergy, or in teenagers.
What are the complications of food allergy?
Anaphylaxis
What is the prognosis of food allergy?
Children often grow out of all, apart form nut/peanut allergies and shellfish.
