Having a dog that lives in the home and older siblings could
reduce the likelihood of egg allergies in infants, a new study by
Murdoch Childrens Research Institute has found.
The study of over 5000 infants investigated the role a wide range
of environmental and demographic factors has on the development of
egg allergy. This included number of older siblings, contact
with other children during childcare, exposure to pets, caesarean
delivery, infant diet, parents' country of birth, family history of
allergy and the use of antibiotics in infancy.
The study found that infants with siblings, particularly young
siblings, and infants with a pet dog inside the home, are less
likely to be allergic to egg at one year of age. In the
study, 10.8% of infants with no siblings were allergic to egg,
however as the number of siblings increased, the incidence of egg
allergy decreased; the rate of egg allergies in infants who had
three or more siblings was only 3.7%. Among infants with one
or more siblings, those with siblings under the age of six years
old were less likely to have egg allergy compared to those with
siblings six years or above.
Researchers also found a link to dog ownership, with the rate of
egg allergies in infants who had no dogs at 10.2%, while among
those who had a dog which was allowed inside the house, the rate of
allergies dropped to 5.9%.
Lead researcher, Doctor Jennifer Koplin said the findings provide
further support for a role of the hygiene hypothesis, in
combination with genetic factors, in the development of
"Our study showed exposure in the first year of life to siblings
and dogs may decrease the risk of subsequent egg allergy.
This could be due to the fact contact with young siblings and pets
may have a protective effect by exposing children to infections and
The study showed evidence of a protective effect of having a dog
inside the house on egg allergy, even among those with those with
no family history of allergic disease.
The study, which was published online today in the journal,
Allergy, also found the strongest risk factor for egg allergy was
having one or more parents born in East Asia. Interestingly,
parents born in East Asia were less likely to report a history of
allergies themselves, while their infants were at an increased risk
of egg allergy and eczema.
Principal Investigator Professor Katie Allen said to date risk
factors for egg allergy have remained largely unknown, and by
understanding these, it may be valuable in understanding the
development for other allergic diseases later in
"We have previously shown that later introduction of egg is
strongly associated with risk of egg allergy, combined with this
knowledge, these new findings and our other allergy research, we
are adding to a growing amount of evidence which is starting to
identify possible causes of allergies."
Read the full paper
Reducing the chance of food allergy developing in children
As a parent, you want to know whether you should act now to change
factors in your life to prevent your children from developing food
allergy. There are theories about why food allergies are more
prevalent. So the advice to patients, and to you, to prevent food
allergy in your child are only recommendations based on the latest
and best data available.
Professor Katie Allen, along with A/Professor Mimi Tang have
written a book titled 'Kid's Food Allergies for Dummies', which
outlines the below four simple steps you can take to help prevent
food allergy in your child.
1. Breastfeed for at least six
If you can breastfeed (and we understand not all mothers are able
to), we advise that you do so until your baby is at least six
months old, because some evidence suggests that breastfeeding for
the first four months of life and also introducing a food while
your baby is still breastfeeding may prevent food allergy.
2. Introduce solids at around six
We recommend that you expose your baby to a wide and varied diet
early on - at around four to six months of age. If your child
hasn't experienced an allergic reaction to a food, no reason exists
to avoid any particular food with the hope of preventing an
3. Let babies get down and
Some evidence suggests that people in westernized countries need
to expose themselves to more (healthy) bugs rather than stay too
clean. Evolving evidence suggests that children exposed to a
broad range of 'good bugs' may be protected against food
4. Get some sunshine in your
Evolving evidence suggests that children without enough vitamin D
(either through insufficient sun exposure or through a deficient
diet) are at increased risk of food allergy. Try to optimise
your child's exposure to sunlight and increase vitamin D intake
*Excerpt taken from Chapter 3 - Preventing Food Allergy in