Lecture 12: Infant/Child Allergies Flashcards

1
Q

Allergy definition

A

When a person reacts to a substance in the environment that is harmless to most people

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are common allergies?

A

Dust mites, pets, pollen, insects, moulds, medications and foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many people will develop allergies at some time during their life?

A

1 in 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many children will develop eczema?

A

1 in 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What percent of children have a food allergy?

A

5-10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What percent of adults have a food allergy?

A

2-4%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is atopic disease?

A

A genetic tendancy to develop allergic disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A child/person with atopy produces elevated…

A

IgE antibodies after exposure to enviornmental allergens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is IgE?

A

A type of immunoglobulin antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Atopic diseases present with one or more of?

A
  • Asthma
  • Allergic rhinitis
  • Eczema or hives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is allergic rhinitis?

A

Also known as Hay fever, is a type of inflammation in the nose which occurs when the immune system overreacts to allergens in the air
- conjunctivitis (nose/eyes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If someone has one atopic disease…

A

They are more likely to develop one of the other two (or both)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is atopic dermatitis?

A

Inflammation of the skin - reddened, swollen, itchy, weeping skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a food allergy?

A

An immune mediated hypersensitivity reaction to a food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are hives (urticaria)?

A

Itchy, raised lumps on the skin, can occur anywhere on the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is typically the first atopic disease to manifest; usually in early infancy?

A

Eczema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What percent of children with eczema have progression to asthma and/or rhinochonjunctivitis?

A

40%
- Most develop respiratory symptoms before 5 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is progression in atopic disease termed as?

A

The atopic march

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Approx. what percent of infants with eczema will also have or develop a food allergy?

A

40%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Majority of children with asthma develop symptoms by what age?

A

6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is wheezing?

A

Sign of asthma; high-pitched, whistling noise than usually occurs with exhaling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Not all children who have wheezing develop asthma AND…

A

Not all children with asthma wheeze

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What percent of children have at least one wheeze episode before 3y?

A

50%
- BUT only one-third will develop asthma before age 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the two types of adverse food reactions?

A
  • Immune mediated (primarily food allergy)
  • Non-immune mediated (primarily food intolerance)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 4 types of immune mediated food reactions?

A
  • IgE mediated
  • Non-IgE mediated
  • Mixed IgE and non-IgE medicated
  • Cell mediated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are IgE mediated reactions?

A

Most common type of allergic response:
- Involves antibodies (+ve sIgE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How do we test for IgE mediated allergies?

A

Measure levels of IgE and can be backed up with a skin prick test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are non-IgE Medicated responses?

A

Immune response - centered usually in the gut, less immediate, do not produce antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are mixed IgE and Non-IgE mediated responses?

A

A combination expressing a range of symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are cell-mediated responses?

A

immune reactions that involve T cells (a type of white blood cell) rather than antibodies (e.g. contact dermatitis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is an IgE mediated food allergy?

A

An immune mediated hypersensitivity reaction to food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How does IgE work to mediate the food response?

A

The antibodies identify food proteins and signals the immune system to react

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are mast cells?

A

The first line of defence in an IgE mediated food allergy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where are mast cells found?

A

Skin, lunges, nose, mouth, blood and gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What do mast cells contain?

A

Histamines which are released and increase blood flow and cause inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How many foods are responsible for 90% of all allergic reactions to food?

A
  • Milk
  • Eggs
  • Fish
  • Shellfish
  • Treenuts
  • Peanuts
  • Wheat
  • Soybeans
  • Sesame
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the common symptoms of a food allergy?

A
  • Swelling, hives, or welts
  • Nausea and vomiting
  • Becoming pale and floppy
  • Difficulty breathing
38
Q

What are the most commonly consumed major food allergens among NZ infants?

A
  • Egg
  • Dairy
  • Wheat
39
Q

Which food allergies are most likely to be outgrown?

A
  • Cows milk
  • Egg
  • Wheat
  • Soy
40
Q

Which food allergies are most likely to be persistent?

A
  • Peanuts (75% persistent)
  • Treenuts (90% persistent)
  • Fish, shellfish (80% persistent)
41
Q

10% of people who have a cows milk allergy will also have a…

A

Soy allergy

42
Q

20% of people who have a wheat allergy will also have a reaction to…

A

Gluten

43
Q

Food intolerances are…

A

Non-immune mediated

44
Q

Non-immune mediated responses are less common in…

A

Infants under 2

45
Q

What are the types of non-immune mediated responses?

A
  • Metabolic (FODMAP)
  • Pharmacologic
  • Toxic
  • Other/Unidentified
46
Q

What are non-immune mediated reactions?

A

An adverse reaction to a food that does not involve the immune system (do not produce IgE antibodies)

47
Q

What are common non-immune mediated reactions?

A

Non-protein substances such as:
- CHO
- Chemicals
- Food additives
- Toxins
- Irritants

48
Q

What are common non-immune mediated reaction symptoms?

A

Can vary and include:
- Diarrhoea
- Nausea
- Cramping
- Headache

48
Q

How long do non-immune mediated reactions take to kick in?

A

Usually less immediate/delayed up to 20 hours after a food is eaten

49
Q

How are non-immune mediated reactions commonly diagnosed?

A

Typically elimination and reintroduction

50
Q

What percent of parents reported food allergies?

A

12.6%
- Over-diagnosed by parents

51
Q

What were the two most common food allergies reported by parents?

A

Cows milk and secondly egg

52
Q

Why do we not use allergy testing as a screening tool?

A

Can cause unnecessary exclusion, there is a high prevalence of false positives

53
Q

How do skin prick tests diagnosis allergies?

A

If weal diameter is greater than 3mm

54
Q

What are examples of serum specific IgE blood tests?

A

EAST = Enzyme Allergosorbent Test
RAST = Radio-Allergosorbent Test

55
Q

What is the scale for Serum specific IgE blood tests?

A

0 = Not detected
1 = Low
2 = Low/moderate
3 = Moderate
4 = High
5 = High
5 = Very High

56
Q

What are examples of unorthodox testing methods?

A
  • Hair analysis
  • Iridology
  • Cytotoxic food testing
  • Vega Testing
  • Pulse Testing
  • Kinesiology
57
Q

What is wrong with unorthodox testing methods?

A

They have no scientific basis, are unreliable and provide non reproducible results

58
Q

What are the adverse consequences of unorthodox testing methods?

A
  • False positives
  • Expensive
  • Result in unnecessary dietary avoidance, can lead to malnutriton
59
Q

Why is there a global rise in food allergies? (GHSMD)

A
  • Genetics and environment
  • Hygiene hypothesis
  • Skin exposure (food based skin products)
  • Methods of food processing
  • Delayed introduction of allergenic foods
60
Q

What is the hygiene hypothesis?

A

Proposes that less exposure to infection in early life is associated with an increased change of developing allergies

61
Q

Genetic influence is likely….

A

Multifactorial with offspring inheriting ‘atopy genes’

62
Q

What does it mean that genetic factors have a strong hereditary component?

A

If both parents are affected by an atopic disease, 40% of offspring will be affected

63
Q

What are environmental factors that influence the rise in food allergies? (MWEH)

A
  • Migration differences (low to high atopy country)
  • ‘Window of opportunity’
  • Exposures
  • Hygiene hypothesis
64
Q

What is the critical window of time?

A

Starts already in utero and ends in school age depending on the kind of exposure

65
Q

What is the dual allergen exposure hypothesis?

A

suggests that food allergies develop through two distinct pathways: sensitisation occurs when allergens are absorbed through the skin, while tolerance develops when allergens are introduced via the gastrointestinal tract at an early age - early controlled oral exposure to allergens to potentially prevent food allergy is important

66
Q

What does evidence say about maternal exclusion

A

That there is no protective effect (don’t avoid, if anything encourage oral exposure)

67
Q

What do recent studies suggest the presence of might support the induction of tolerance towards solid foods in infants?

A

Maternal dietary proteins in amniotic fluid, cord blood and human milk

68
Q

Breastfeeding during the period that solid foods are first introduced may help reduce what?

A

Reduce the risk of the infant developing allergies, although evidence for this is low

69
Q

There is moderate evidence that probiotics during pregnancy and breastfeeding may help prevent what?

A

Ezcema in early life - controversial

69
Q

Up to 3 serves per week of what may be beneficial during breastfeeding and pregnancy to help prevent eczema in early life?

A

Oily fish (contains omega 3 fatty acids)

70
Q

Why can recommendations about probiotic supplements not currently be made?

A

Because the optimal species and dose of probiotics is unclear

71
Q

What does evidence say about partially or fully hydrolyzed formulas for the prevention of eczema, food allergy, asthma or allergic rhinitis?

A

That there is no evidence to support it

72
Q

If breastfeeding is not possible, what should be given?

A

A cows milk based formula

73
Q

Cows milk vs. Soy or Goat milk formula for reducing risk of evidence

A

There is no evidence that soy or goats milk formula reduces the risk of allergies compared with cow’s milk formula

74
Q

When should the introduction of solid foods be?

A

Around 6 months, not before 4 months and preferably whilst breastfeeding

75
Q

When should common food allergens be introduced? (Oral Exposure)

A

Before 12 months of age
- Including high risk infants

76
Q

How should new common allergens be introduced?

A

One at a time, around 1 or 2 days apart

77
Q

Once a common allergen food is tolerated…

A

Continue to give regularly to maintain tolerance

78
Q

Why does smearing food on the skin not help to identify food allergies?

A

Infants skin is very sensitive and skin irritation does not equate to food allergy
- Smearing on skin of a child with eczema may increase the risk

79
Q

Use skincare products that….

A

DO NOT contain food protein

80
Q

How should skin be treated for those with eczema?

A

Apply moisturiser at least twice a day, avoiding those that contain food products

81
Q

How do we diagnose Non-IgE mediated food allergies?

A

clinical symptoms and will
have negative SPT/serum IgE testing

82
Q

When should oral exposure be done?

A

From 6 months and before 12 months of age, introduce all allergen foods (e.g. egg, peanut, treenut, milk, soy, wheat, fish, seafood, sesame) into the
infant’s diet, and offer regularly once introduced.

83
Q

Food intolerance is more common in?

A

Older children and adults

84
Q

What is the most common food intolerances?

A

lactose and fructose intolerance, other FODMAP foods

85
Q

Food intolerance can be related to reduction in….

A

Digestive enzymes e.g. lactase

86
Q

Babies reacting to cow’s milk will also react to…

A

Other mammalian milks i.e. goat and sheep milk

87
Q

Why is lactose free formula not suitable for babies who react to cows milk?

A

not suitable as baby is reacting to the protein in the milk

88
Q

What age should soy formula not be?

A

Not for under 6 months

89
Q

What are infant milks for IgE and Non-IgE cows milk protein allergy?

A
  • Extensively hydrolysed formula
  • Rice formula
  • AA formula