Food Allergy Flashcards
What are food allergies?
An abnormal immunological response to food
What happens in food allergy?
There is a pathological immune response to a specific food protein
What antibody is the usual mediator for an allergic reaction to food?
IgE
What is a primary food allergy?
Where children react on first exposure
Are food allergies most commonly primary or secondary?
Primary
What are secondary food allergies most commonly associated with?
Cross-reactivity between proteins on fresh fruit/veg/nuts and those in pollen
What do non-IgE mediated food allergies invovle?
GI disturbance, typically hours after ingestion
What is a non-immunological hypersensitivity to food called?
Intolerance
What are the most common allergies in infants?
- Milk
- Egg
- Peanut
What are the most common allergies in older children?
- Peanut
- Tree nut
- Fish
- Shellfish
What are the risk factors for developing food allergies?
- Family history
- Vitamin D deficiency
- Obesity
- Hygiene hypothesis
What are the symptoms of IgE mediated food allergies?
- Urticaria
- Facial swelling
- Anaphylaxis
When do symptoms of IgE mediated allergic reactions to food occur?
10-15 minutes after ingestion
What are the symptoms of non-IgE mediated food allergies?
- Diarrhoea
- Vomiting
- Abdominal pain
- Faltering growth
What is the gold standard investigation for both IgE and non-IgE mediated food allergies?
Double blinded placebo-controlled food challenge
What happens in a double blinded placebo-controlled food challenge?
The child is given increasing amounts of food or placebo and should be performed in hospital with full resuscitation available
What other tests can be used to check for IgE mediated food allergies?
- Skin prick test
- Measurement of specific IgE antibodies in blood
What can be used to look for non-IgE mediated food allergies?
Endocsopy and intestinal biopsy
How can food allergy be managed?
- Avoid relevant foods
- Advice from dietician
- Written management plan for reaction
- Antihistamines for mild reactions
- IM adrenaline for severe reactions
What are the complications of food allergies?
- Anaphylaxis
- Blood in stools (non-IgE mediated)
- Food protein induced enterocolitis syndrome (non-IgE mediated)
