HUNT243 exam

What is an allergy?

When a person reacts to a substance in the environment that is harmless to most people such as dust mites, pets, pollen, insects, moulds, medications and food

What is the prevalence of allergies?

1 in 5 will develop at some point, 1 in 10 will develop eczema, 5-10% of children have a food allergy compared to 2-4% of adults

What is atopic disease?

A genetic tendency to develop allergic disease where a child/person with atopy produces elevated IgE antibodies after exposure to environmental allergens

What do people with atopic present with one or more of?

Asthma, allergic rhinitis and/or eczema or hives

What is the cascade of allergies associated with atopic disease?

Once people have one of the common atopic diseases they are more likely to develop another and have an increased risk of developing a food allergy

What is atopic dermatitis?

Also called eczema, inflammation of the skin causing reddened, swollen, itchy and weeping skin

What is asthma?

An allergic inflammation of the bronchial airways producing swelling, narrowing and mucus which leads to difficulty breathing

What is allergic rhinitis?

Also know as hay fever, a type of inflammation in the nose which occurs when the immune system over reacts to allergens in the air

What is a food allergy?

An immune mediated hypersensitivity reaction to a food

What is hives?

Also know as urticaria causing itchy, raised lumps on the skin which can occur anywhere on the body

What is the first atopic disease to manifest?

Eczema in early infancy

What is the atopic march?

Eczema into asthma as up to 40% of children with eczema go on to develop asthma or rhino conjunctivitis with most experiencing respiratory symptoms before 5 years of age

Is eczema a major risk factor for a food allergy?

Yes as 40% of affected infants have or develop a food allergy

What is wheezing?

A sign of asthma involving a high pitched whistling noise that usually occurs with exhaling

When do people with asthma develop symptoms?

Majority by age 6 but many even develop symptoms by age 3

How common in wheezing with people who have asthma?

Not all children who have wheezing develop asthma and not all children with asthma wheeze, up to 50% of children have at least one wheeze episode before 3 years but only one third will develop asthma before 6

What is an IgE mediated food allergy?

An immune mediated hypersensitivity reaction to food where IgE antibody identifies food proteins and signals the immune system to react

What cells are the first line of defense in an IgE mediated food allergy?

Mast cells in the skin, lungs, nose, mouth, gut and blood which contain histamines which are released and increase blood flow and cause inflammation

What are the 9 major food allergens?

Milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame

What are some symptoms of food allergies?

Ranging from mild to moderate to severe including swelling, hives, nausea paleness and difficulty breathing

What are the most commonly consumed food allergens in NZ infants?

Dairy, wheat, egg, soy, peanut, seafood, sesame and tree nuts

What food allergens are most likely outgrown?

Cows milk, egg, wheat and soy

Which food allergens are most likely persistent?

Peanut, tree nuts, fish and shellfish

What are non-immune mediated reactions?

An adverse reaction to a food that does not involve the immune system and doesn’t produce IgE antibodies after exposure such as reactions to carbohydrates, chemicals, food additives, toxins and irritants

What are symptoms of non-immune mediated reactions?

They can vary and include diarrhoea, nausea, cramping or headache, the reactions are usually less immediate and delayed up to 20 hours after a food is eaten and diagnosed through elimination and reintroduction

Why does lactose intolerance occur?

Due to less lactase enzyme

How do skin prick tests for allergies work?

The IgE antibody specific response produces different sized weals

What are serum specific IgE blood tests?

Either EAST or RAST and measures level of the antibody in peoples blood on a scale from 0-6

What are methods of testing for allergies in NZ?

Skin prick tests of serum antibody blood tests

What are some unorthodox methods of allergy testing?

Cytotoxic food testing, vega testing, kinesiology, iridology, pulse testing and hair analysis but that are unvalidated, not supports and can result in lots of false positives so unnecessary

What are some possible explanations for the global rise in food allergies?

Genetics and environment, hygiene, development of allergy to food by skin exposure, methods of food processing and delayed introduction of allergenic foods

How do genetics influence rise in food allergies?

Genetic influence is likely multifactorial with offspring inheriting atopy genes and there is a strong hereditary component where if both parents are affected by an atopic disease then 40% of offspring will be affected

How does the environment influence rise in food allergies?

Due to migration differences and low to high atopy in different countries, this may be due to the window of opportunity in the first few years of life when the developing immune system is susceptible to being directed along an atopic pathway

What are extra environmental factors influence food allergies?

Different triggers or exposures that indirectly influence programming of a reduced expose to infectious diseases and microbial products

How does topical application of allergies influence food allergies?

Children are protected by eating the food early but may become allergic by skin exposure in absence of protective oral exposure called the dual-allergen exposure hypothesis

How does maternal diet influence food allergies?

No found protective effect of maternal exclusion during pregnancy of common allergen foods and the presence of these foods in fluids might support the induction of infant tolerane

How does maternal diet and breastfeeding influence food allergies?

Exclusion of common allergen foods from the maternal diet is not recommended and should keep breastfeeding up to 6 months old and when introducing solid foods

What extra foods might be recommended to reduce risk of allergies during pregnancy?

Oily fish and probiotics

How does infant formula influence food allergies?

If no breastmilk then cows milk alternative recommended, no evidence for hydrolysed formulas supporting a protective role and shouldn’t be main source of milk for infants under 12 months

How does complementary feeding relate to allergies?

Introduction should be around 6 months but not before 4 months, common food allergens should be introduced in an age-appropriate form before 12 months old, new allergens should be introduced one at a time one to two days apart and once introduced should be given regulary

How should we treat babies skin in relation to allergies?

We shouldn’t smear food on a babies skin and shouldn’t use skincare products that contain food proteins

What are the areas of a dietitian’s role in food allergy?

Education, identification, avoidance, safe substitutes, nutrition, reaction management and reintroduction

What does the education role involve?

Explaining the difference between allergy and intolerance

What does the identification role involve?

Finding or identifying the trigger food

What does the avoidance role involve?

How to avoid the allergen, including label reading

What does the safe substitutes role involve?

Food alternatives and adapting family meals

What does the nutrition role involve?

Growth monitoring, diet analysis, formula prescription and supplements (e.g. vitamin D)

What does the reaction management role involve?

Knowing how to manage a reaction

What does the reintroduction role involve?

Milk and egg ladders and safe reintroduction

What formula options exist in NZ?

Cow’s, goat’s, sheep’s, soy, rice, oat toddler, extensively hydrolysed, lactose free and amino acid formulas

Why are goat and sheep milk formulas not suitable for infants with cows milk protein allergy?

Babies reacting to cow’s milk will also react to other mammalian milks

Why is lactose free formula not suitable for infants with cows milk protein allergy?

The baby is reacting to the protein in the milk, not the lactose

What are the key points about soy formula?

Many infants who react to cow’s milk also react to soy, it should not be given under 6 months but can be given after 6 months, it is not PHARMAC funded

When is extensively hydrolysed formula (eHF) not suitable, and is it funded?

It is not suitable for infants with severe cow’s milk protein allergy or anaphylaxis, it is PHARMAC funded

Is rice formula PHARMAC funded?

No it isn’t

Is amino acid formula PHARMAC funded?

Yes but can be out of stock

What education and identification advice was given to Teddy’s family in case study?

Continue breastfeeding (Mum keeps all allergens in her diet) and learn to read food labels for allergens, introduce the other allergens (tree nuts, shellfish) and continue tolerated allergens

What do “CONTAINS” and “MAY CONTAIN” mean on food labels?

“Contains” means avoid, “may contain” may be okay depending on the severity of the allergy

What should you check in an alternative milk?

That it gives at least 120 mg calcium per 100 mL

How do the alternative milks compare?

Soy milk is the best choice (good protein, fat, energy), oat milk gives good energy and some protein, rice milk gives good energy, with a maximum of 300 mL per day, almond, coconut and cashew milks are low in energy, protein and fat, so they are a last resort

What yoghurt alternatives were mentioned in case study as good options?

Home-made soy yoghurt (vegan starter plus soy milk), soy yoghurt, coconut yoghurt (few have calcium, except The Collective Dairy Free Pouch), and cashew yoghurt (Little Island has calcium)

How do you maintain tolerance to allergens already tolerated?

Give wheat, sesame, soy, fish, seafood and tree nuts regularly

How were tree nuts and seafood introduced to Teddy in case study?

One tree nut at a time as a butter or powder, starting at ⅛ teaspoon and increasing, and trialling seafood such as prawn

What is the evidence for baked milk in cow’s milk allergy?

Kim et al. (2011) found that dietary baked milk accelerates the resolution of cow’s milk allergy in children

What dietary advice helps prevent food allergy?

Eat a diverse, high fibre diet with whole grains, vegetables, fruit, lean proteins, nuts/seeds and milk products and to include all allergen foods while pregnant and breastfeeding

When should allergen foods be introduced to babies?

From 6 months and before 12 months, even in high-risk babies (e.g. a sibling with allergy)

What is the vitamin D advice for allergy prevention?

Very low vitamin D may increase risk, so supplementation is recommended for high-risk individuals in pregnancy, vitamin D is recommended for the baby until 12 months of age

What are the extra food allergy prevention tips?

Choose vaginal birth if possible, aim to breastfeed exclusively for 6 months and continue alongside food introduction, avoid known food allergens on baby’s skin (e.g. almond oil)

When should solids be started?

From around 6 months when the baby is developmentally ready, but not before 4 months, aim for a diverse diet

How do you introduce each allergen?

Egg: boiled egg mashed into pureed vegetables. Peanut: a small amount smeared on the spoon. Tree nuts: blitzed to a powder in porridge, starting at ¼ teaspoon and increasing. Wheat: pasta or bread. Soy: bread or tofu. Sesame: seeds in porridge. Fish: pan fried finger food. Seafood: pan fried prawns as a finger food

What are the safety tips when introducing allergens?

Give food in the morning, have another adult present if you’re worried, do it at home, if you live very rurally, do it near a main centre with a medical centre or hospital (when open)

What is the step-by-step process for introducing a food?

Put a small amount in the baby’s mouth and look for a reaction, wait 30 minutes, then give another small amount, increase the amount the next day

How often should an allergen be given once it’s in the diet?

Keep it in, ideally twice a week every week until around 2 years of age

When is infant formula used?

When an infant is not breastfed or breastfeeding isn’t going well. It should be used until the infant is 1 year old

What are the three types of infant formula products?

Infant formula (0 to <12 months), follow-on formula (6 to <12 months), and infant formula products for special dietary use (e.g. allergy formula, used under medical supervision)

Which type of formula is the most common?

Standard infant formula

Is follow-on formula necessary?

No. Health guidelines say babies can safely stay on standard infant formula until their first birthday

Why do infant formulas contain more iron than breast milk?

Iron is more absorbable in breast milk, so formulas contain more to compensate

Which NZ standards regulate infant formula?

Standard 2.9.1 (Infant Formula Products) and Schedule 29 (Special purpose foods) in the Australia New Zealand Food Standards Code

What does Standard 2.9.1 cover?

Mandatory nutrient content for infant and follow-on formula, plus labelling requirements, including prohibited claims, images and symbols

What does Standard 1.3.1 control?

Which food additives can be added, and their maximum limits

What does Standard 1.6.1 cover?

Processes and systems to minimise microbiological risks such as Salmonella

What is the international standard for infant formula?

Codex Alimentarius (WHO and FAO), CODEX STAN 72-1981

Why is marketing of infant formula tightly regulated?

Because babies should be breastfed up to 6 months. Labelling restrictions mean infant formula can’t be marketed heavily

How does marketing regulation differ for follow-on formula?

There is less regulation of follow-on formula marketing

What is Proposal P1028?

A review of infant formula regulations to keep them safe, suitable and in line with current science, market developments and international context. It revises 5 standards and 8 schedules, with a 5-year transition period

What are the key amendments in P1028?

Prohibiting cross-promotion (e.g. using the infant formula tin to promote follow-on formula), mandating a Nutrition Information Panel (NIP) to help caregivers make informed choices, and restricting the sale of special medical purpose products

What did NZ do about the amended P1028 standard, and why?

NZ opted out on third-country trade grounds, because of concerns that prohibiting ingredient statements could hurt NZ exporters’ global competitiveness

What did Cheung et al. (BMJ 2023) find about infant formula health claims?

41 ingredient groups were tied to 1884 claims. 50% weren’t specific to an ingredient, only 26% were supported by evidence, and 88% of that evidence was industry-funded or had industry-linked authors

What does the Lancet series say about commercial milk formula marketing?

Companies exploit emotions, aspirations and misleading science to generate sales at the expense of families’ health and rights

Why is homemade infant formula unsafe?

Infants have immature kidneys and GI tracts, recipes can exceed upper limits for vitamin A and be high in sodium, protein and iron, and ingredients carry microbiological risks

Which microbiological risks come with homemade formula ingredients?

Honey (botulism), runny eggs (Salmonella), raw liver, and raw milk (Listeria and Salmonella)

What happened with Pete Evans in 2015?

His Paleo DIY “formula” (liver, cod liver oil, bone broth) book was shelved days before release. The self-published version rebranded it “Happy Tummy Brew”, moved it to the 6 to 12 month section and recommended it only once a day

Who criticised Chelsea Winter’s 2020 recipe, and what was it?

Dr Amy Lovell (University of Auckland) criticised her “dairy-free toddler milk” recipe

What should not be given as a drink to babies under 12 months?

Cow’s milk, plant-based milks (soy, oat, almond, coconut), condensed milk and evaporated milk

What are the two types of milk protein?

Casein and whey

How do whey and casein differ in digestion?

Whey is digested quickly. Casein forms curds that are digested slowly, resulting in slower gastric emptying

What are the casein:whey ratios in breast milk and formulas?

Breast milk 40:60, whey-dominant formula 40:60, casein-dominant formula 80:20

Why is casein-dominant formula cheaper?

It requires the least modification

What are the dominant whey and casein proteins in breast milk?

Alpha-lactalbumin (whey, low in formula) and beta-casein