Allergy in children Flashcards
Food allergy definition
adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food
IgE mediated food allergy features
quick onset
anaphylaxis
well-defined mechanism
easy to diagnose
validated tests
Non-IgE mediated allergy features
delayed onset
eczema/GORD
mechanism unclear
harder to diagnose
no validated tests
Allergy focussed history questions
symptoms and signs
timing from ingestion to symptoms
frequency of reactions
time of most recent occurrence
quantity of food needed to evoke reaction
treatment given
what is/is not in diet and why
history of atopy
feeding history - age of weaning, breast, formula
cultural and religious factors
any response to elimination and reintroduction
Disorders associated with allergy
eczema
asthma
animal dander allergies
house dust mite allergies
allergic rhinitis
eosinophilic oesophagitis
constipation
poor growth
Allergy testing
specific IgE
skin prick testing
oral food challenge - gold standard
Pathophysiology of IgE-mediated allergy
sensitisation to allergen
exposure to allergen
What does the wheal size on skin prick testing suggest?
likelihood of allergy
wheal size not associated with allergy severity
Management of food allergy
awareness
avoidance
asthma control
antihistamine
adrenaline autoinjector
What antihistamines are used in children?
second generation H1 antihistamines preferred - better safety profile, longer duration of action
cetirizine first line
Absolute indications for adrenaline autoinjectors
previous cardiovascular or respiratory reaction to food, insect sting or latex
food allergy and coexistent moderate/severe or poorly controlled asthma
exercise-induced anaphylaxis
idiopathic anaphylaxis
Relative indications for adrenaline autoinjector
any reactions to small amounts of food eg. airborne food allergen
previous mild reaction to peanut or tree nut
remoteness of home from medical facilities
allergic reaction to food as adolescent
Describe pollen food syndrome
distinct clinical presentation
mild oropharyngeal symptoms
coexistent hayfever
usually presents later
Which allergies do children often grow out of?
milk
egg
wheat
Which allergies typically persist into adulthood?
peanuts
tree nuts
seafood
seeds
Where to implement the milk ladder
non-IgE allergy = at home
IgE allergy = in hospital
Can peanut allergy be prevented?
early introduction of peanuts significantly decreases the development of peanut allergy among children at high risk for the allergy
