Are allergies increasing?

Recent Australian research shows that 1 in 10 babies will develop a food allergy by one year of age. The reasons for the ongoing increase in allergic conditions such as food allergy, eczema and hay fever are complex and we still don’t fully understand them.

Although babies with a family history of allergy have a higher chance of developing an allergy, babies with no family history can still develop allergies.

Why is food allergy increasing?

We currently do not know why food allergy has increased so rapidly in recent years, particularly in young children. It appears to be a mix of a western lifestyle and environmental factors – with no single trigger factor.

Possible reasons include:

• Delaying the introduction of common allergy causing foods such as egg, peanut or tree nuts.
• The hygiene hypothesis which suggests that less contact with microbes in early childhood may increase the chance of developing allergy. A more recent version of the hygiene hypothesis suggests that the type of the micro-organisms to which the mother and baby are exposed to may be important.
• Methods of food processing food such as roasted versus boiled peanuts or baked egg versus lightly cooked egg, may affect whether the food is more or less likely to cause food allergy.
• Development of food allergy by the skin coming into contact with the food before the food has been eaten by the baby, for example through the use of moisturisers containing foods such as nut oils or cow’s or goat’s milk.
• Use of medicines to decrease gastric acid production.
• Vitamin D status in the first year of life.

These areas require additional research studies, several of which are underway.

Does food allergy run in the family?

Many children with food allergy will have a parent or a sibling who suffers from some type of allergic condition such as eczema (atopic dermatitis), asthma, hay fever (allergic rhinitis) or food allergy.

Most of the time, children with food allergy do not have parents with food allergy. However, if a family has one child with a food allergy, their brothers and sisters have a slightly higher chance of having a food allergy themselves, although that risk is still quite low.

Are all food allergies severe?

Most babies with food allergy only experience mild symptoms. Mild symptoms include hives, stomach/tummy pain or vomiting. Symptoms such as difficulty breathing or talking (vocalising) due to throat or tongue swelling or breathing difficulty, or dizziness due to a drop in blood pressure or tongue swelling, are less common, however these indicate a potentially life threatening severe allergic reaction (anaphylaxis).

If I have a positive allergy test, does this mean I am allergic to the foods?

A positive skin prick test (SPT) or allergy blood test means that the body’s immune system has produced a response to a food, it does not mean that the person is necessarily allergic to that food.

About 1 in 3 people with positive blood allergy tests or skin tests to foods will not be allergic to that food, especially if they have not previously experienced an allergic reaction to that same food when eating it. For this reason, it is not generally recommended to screen people for allergies to foods using these tests.

How accurate are alternative allergy testing methods?

Unproven claims to cure or detect allergy are only strictly regulated by government, medical boards, and advertising regulators, if the practitioner is a registered medical practitioner.

Currently, there are no strict regulations for unproven diagnostic techniques or devices. These devices and tests can be TGA approved in Australia without having to prove that they work.

There are many methods that claim to test for allergy. These include cytotoxic food testing, kinesiology, Vega testing, electrodermal testing, pulse testing, reflexology and hair analysis. These tests have not been proven to work and may lead to unnecessary, costly and (in the case of some changes in diet) dangerous avoidance strategies.

Should I avoid pets?

There is no reason to remove pets from your home unless a person is already allergic to them. Some research studies have shown that having dogs may help lower the chance of children developing allergies.

Will dust mite avoidance measures reduce the risk of allergy and asthma developing?

No, measures to reduce house dust mite are difficult and don’t help to prevent allergies or the onset of allergic rhinitis (hay fever) or asthma. However, if you have confirmed house dust mite allergy then minimisation measures may help reduce symptoms.

Will allergen immunotherapy (desensitisation) prevent allergy?

Allergen immunotherapy or desensitisation is a treatment for someone who already has an allergy.

Allergen immunotherapy does not help to prevent food allergy.

Research suggests that if a child has hay fever (allergic rhinitis), having allergen immunotherapy for their trigger may reduce the chance of the child developing asthma.

Talk to your doctor if you would like to know more about allergen immunotherapy.

Will changing my diet during pregnancy or breastfeeding prevent my baby from developing allergies?

Avoiding the common allergy causing foods including peanut, egg, fish, soy and cow’s milk when you are pregnant or breastfeeding has NOT been shown to reduce the chance of the baby developing allergies, but has been shown to increase the likelihood of lower weight gain by babies.

Therefore, restricted diets during pregnancy or breastfeeding are not recommended for allergy prevention.

If my baby is allergic to a food, should I avoid eating or drinking this food if I am breastfeeding?

Breastfeeding mothers do not need to avoid eating or drinking the food their baby is allergic to unless their baby is reacting to the food in breastmilk, or they have been advised by their doctor to avoid the food.

Removing foods from the mother’s diet unnecessarily puts the mother’s nutritional health at risk, particularly when removing food groups such as milk (dairy) and wheat or removing multiple foods. Mother’s avoiding foods such as milk (dairy), wheat or multiple foods should see a dietitian to make sure they are getting all the nutrition they need.

Will taking fish oil supplements or eating fish prevent allergy?

For pregnant and breastfeeding mums, eating oily fish such as salmon, mackerel, sardines, trout and herring, 3 times a week may help.

Some research shows that consuming the omega-3 fatty acids found in oily fish during pregnancy and breastfeeding may help prevent eczema in early life. There is no evidence that consuming fish oil supplements prevents allergy.

Are probiotics useful in preventing allergies?

Probiotics are good bacteria. We usually think of bacteria as germs that make us sick, but research has shown that probiotics are a good type of bacteria and good for your health.

At this stage, researchers are not sure if probiotics can help to reduce the chance of your baby developing allergies.

There is some research that shows that probiotics taken during pregnancy and breastfeeding may help to reduce the rate of eczema in the baby. However, the type of probiotic and the amount needed is still not clear.

Are there any foods I should not feed to my baby when starting solid foods?

Solid foods should be commenced when your baby is ready at around 6 months of age, and not before 4 months. You should not avoid any foods to prevent allergy.

If you think your baby has an allergy to a certain food, talk to your doctor before giving your baby that food. If there are foods you are not able to feed your baby due to allergy, talk to your doctor and possibly a dietitian.

How often should I feed my baby allergy causing foods once introduced?

Once you have fed your baby the common allergy causing foods, it is important to continue to include these foods in your baby’s meals, ideally at least twice a week until they are 5 years of age. This is important to help prevent your baby possibly developing an allergy after eating the food. If you feed your baby the common allergy causing foods, but your baby does not continue to eat the foods, they could develop a food allergy if they have not eaten the food for some time. There is no clear research to tell us exactly how much of the allergy causing foods your baby needs to eat to prevent food allergy, so it is recommended that you choose small amounts (e.g. 1 teaspoon) to start with and increase the amount as your baby grows and eats more.

As it is important to continue to feed your baby the common allergy causing foods once introduced, you should only feed them the foods that you are able to continue to feed them. Your baby will eventually be eating family foods, so if your family does not eat a particular food, you may choose not to introduce that particular food to your baby, knowing that they are not likely to continue eating it once they are able to eat family meals. You may wish to discuss this with your doctor or an allergy dietitian.

What should I do if my baby already has food allergies?

It is important that you have discussed your baby’s allergy with a doctor so that you have any medications required or prescribed by your child’s doctor.

What should I do if other members of the family have food allergies?

If other members of the family have food allergies, it is still important to introduce that food to your baby, while keeping the family member with food allergy safe.

Does cooking the food remove the allergen?

Cooking some foods such as baking egg and milk, may make some foods less likely to cause allergic reactions. However, this is not always the case, so the decision to give a child a food they are allergic to in a cooked form, should only be made by a clinical immunology/allergy specialist.

If a clinical immunology/allergy specialist thinks a child who is allergic to egg or milk is likely to be able to eat baked milk or baked egg without having an allergic reaction, the child will usually have an oral food challenge to confirm this. Oral food challenges may be done in a hospital setting where medical assistance and facilities are available, as severe reactions can, and do, occur.

Many people allergic to food products cannot eat them whether they are cooked or uncooked, and they should follow the advice of their treating specialist.

If I can't breastfeed, which formula is useful in preventing allergies?

If you are not able to breastfeed or your baby needs supplementary feeding (commonly known as ‘top ups’ or complementary feeds), commercial infant formula may be used until 12 months of age.

Current research does not support the use of partially hydrolysed formulas (usually labelled ‘HA’ or Hypoallergenic) or extensively hydrolysed formulas to prevent eczema, food allergy, asthma or hay fever (allergic rhinitis) in babies or toddlers.

What formula should I use if my baby has a cow’s milk allergy?

If your baby has a cow’s milk allergy, regular infant formula should not be given to your baby and your doctor will recommend an alternative such as soy infant formula, hydrolysed rice formula or a prescription only specialised infant formula depending on your child’s age and medical history.

Most children allergic to cow’s milk will also react to other animal milks such as goat and sheep milk and horse milk, so they should be avoided.

“A2 milk” (from specially bred cows) is claimed to have a number of health promoting properties, but this milk is also not suitable for children with cow’s milk allergy and should not be given.

Partially hydrolysed cow’s milk-based formula (usually labelled ‘HA’ or hypoallergenic) is also not suitable for children with cow’s milk allergy.

Are all reactions to cow's milk due to allergy?

Some reactions to cow’s milk may be due to lactose intolerance, which is caused by the lack of the enzyme lactase, which helps to digest the milk sugar lactose.

Symptoms include diarrhoea, vomiting, stomach pain and gas, which are similar to some of the symptoms of cow’s milk allergy.

Lactose intolerance is uncomfortable but not life-threatening and does not cause symptoms of food allergy such as hives, swelling or anaphylaxis.

Is soy milk or goat's milk better at preventing allergies over cow's milk formula?

No. Research has shown that using soy milk or goats milk formula instead of cow’s milk formula does not reduce the chance of your baby developing an allergy.

How often should babies and children with eczema have a bath or shower?

Babies and children with eczema should bathe regularly – daily if possible, but at least a few times a week if a daily bath is not possible. Bathing in water that is not too warm helps to clean and cool the skin which can help to relieve itching.

Whether bathing or showering, prescribed topical preparations (creams or ointments you put on the skin) and moisturiser should be applied to the skin as soon as your child has been gently patted dry after getting out of the water. It is important that you wash your hands with soap and warm water to remove any allergens or bacteria from your hands before applying creams, ointments or moisturisers to your child’s skin.

How often should moisturiser be applied?

Plenty of moisturiser should be applied to the face and body at least twice a day. Apply moisturiser more often if the skin feels very dry. There is no harm done by applying moisturiser more often. Wash your hands with soap and warm water to remove any allergens or bacteria from your hands before applying the moisturiser.

What moisturiser should parents use on their baby or child?

Moisturisers come in different forms, including ointments, creams and lotions.

Moisturising lotions have a high water and low oil content and are not typically moisturising enough for most babies and children with eczema.

Moisturising creams increase skin hydration and are excellent for everyday use. Moisturising creams can sting active areas of eczema, and if this is the case, an ointment moisturiser is preferred.

Ointment moisturisers provide an excellent protective barrier for the skin. However, they are thicker and greasier and not always tolerated by the child. The thicker the moisturising cream, the longer it lasts and the less often it needs to be applied, however, it should still be applied twice a day.

For allergy prevention, it is important to make sure that moisturisers do not contain food ingredients such as nut oils, cow’s milk or goat products.

Is there anything to avoid when choosing skin products for babies and children?

It is generally recommended to avoid products containing perfume or fragrance as these can irritate the skin. Plant extracts (such as lavender oil) can also irritate the skin so are best avoided.

For allergy prevention, it is important to make sure that moisturisers do not contain food ingredients such as nut oils, cow’s milk or goat products.

Is it safe for massage oils to be used on infant skin?

Yes, however it is recommended to avoid oils containing food ingredients such as almond oil, or other nut oils, on the skin of babies and children with eczema as this may increase the chance of the child developing a food allergy.

Moisturiser can be massaged into the skin if you are wanting to use it for baby massage and this is often a better option to keep the skin soft and well moisturised.

Wash your hands with soap and warm water to remove any allergens or bacteria from your hands before applying the moisturiser.

Are food allergies more common in children with eczema?

Babies with moderate or severe eczema have an increased chance of also having a food allergy.

This does not mean that the food allergy is the cause of the eczema and therefore the removal of the food will not result in eczema cure. However, if a child is allergic to a food, they should not be fed that food.

If there is no food allergy, very occasionally a trial of removing certain foods may be recommended in combination with other treatments for the management of severe eczema. This should only be done under the supervision of a clinical immunologist/allergy specialist and an accredited practising dietitian, with experience in food allergies. This is because there is a risk of malnutrition and of your child actually developing a food allergy to the foods removed from the child’s diet.

Are cortisone creams and ointments safe?

Yes. Cortisone creams and ointments (also referred to as steroid creams and ointments) are extremely safe when used correctly. It is important to apply them to all affected areas, not just the worst areas, until the eczema completely clears.

Parents are often told these creams or ointments will thin the skin, but this is very rare as eczema tends to thicken the skin.

There is very little absorption into the body so natural cortisone production is not affected. Poorly controlled eczema has much more potential to harm a child than using cortisone creams.

For example, under-treated eczema is prone to infection, sleep is disturbed by itching and this can lead to unsettled daytime behaviour, lack of concentration and may impact on learning ability.