Food allergy and intolerance

Question 1

Definition of a food allergy

Answer 1

pathological immune response mounted against a specific food protein

Question 2

Definition of a food intolerance

Answer 2

a non immunological hypersensitivity reaction to a specific food

Question 3

Clinical feature of igE mediated food allergy

Answer 3

1. Occurs acutely after exposure to allergens (10-15mins
2. Urticaria –> Facial swelling –> anaphylaxis
3. Wheeze –> stridor

Question 4

Clinical feature of food intolerances

Answer 4

1. Diarrhoea, vomitting or abdominal pain

2. Failure to thrive

Question 5

How are IgE mediated food allergies diagnosed?

Answer 5

1. RAST testing - skin prick tests which screens for IgE mediated food allergies

Question 6

How are non IgE mediated food allergies diagnosed?

Answer 6

1. History and clinical examination
2. Consider endoscopy and clinical biopsy if diagnosis is supported by eosinophillic infiltrates
3. Gold standard Ix
   - exclusion of relevant food under dietician supervision
   - followed by double blind placebo and reintroduction of food

Question 7

Management of food allergy

Answer 7

1. Avoid triggering food ( advice from paed dietician)

2. Mx of allergic attacks from anihistamines to administrating adrenaline in anaphylaxis

Question 8

What else must patients with food allergies be screened for?

Answer 8

1. atopic eczema and food allergies often co exist particularly igE mediated food allergies