Have you noticed that food allergies seem to be on the rise? It seems that nearly every adult can remember the onechild in his or her school who suffered from a life-threatening food allergy. However this is becoming a more common occurrence. Between 1997 and 2007 the prevalence of reported food allergies in children under 18 years of age in the US has increased by 18% (1). While food allergies do tend to run in families and often occur alongside other conditions, such as asthma, the reason for this increase in diagnosis is still unknown. Some speculate that it has to do with our obsessive desire for cleanliness with the use of antibacterial hand sanitizers, disinfectants, and home cleaning products which can all affect the bacterial flora in our gut. Exposure to some bacteria may protect our immune system from overreacting. However, this explanation still needs more research. Sending your kids to play in the dirt might not do anything to help prevent them from developing allergies.

 

Prevention

Messaging around food allergies has changed considerably over the past few years, so it’s no wonder that a great deal of confusion exists. Mothers were once told not to consume any potential allergens like nuts during pregnancy and lactation as a measure to prevent their children from developing food allergies. It’s now believed that maternal consumption of these foods will not affect the development of allergies. Therefore, unless the mom herself is allergic to a given food, there is no reason to avoid it during pregnancy or breastfeeding

 

Symptoms

Symptoms of food allergies can range from fairly subtle to severe. A child may develop a rash anywhere on the body, hay fever, or asthma, in addition to the food allergy. This is known as the atopic march (2). Additional symptoms of a food allergy may include: stuffy or itchy nose, sneezing, itchy and teary eyes, vomiting, stomach cramps, diarrhea, swelling or tightening of the throat, tingling or swelling of the tongue and difficulty breathing.

 

Diagnosis

What should you do if you suspect that your child has a food allergy? Obviously, if they are suffering from immediate and severe symptoms, as in the case of anaphylactic shock which can lead to unconsciousness and death, you should bring them to the nearest emergency department. If you think you or a family member has an allergy, request a referral from your pediatrician or family doctor to see an allergist. An allergist is a physician with specialized training to diagnose, treat and manage allergies and asthma. The only tests capable of accurate allergy diagnosis are skin prick and certain blood tests that can be done when skin tests are not possible.

 

Skin prick tests are done by pricking the skin with a small needle. A small amount of the potential allergen is then placed on the skin at the location of the prick. If an allergy to the food exists a reaction will occur within about 15 minutes. Generally the area will become red and may itch. If there is no change to the skin, there is no allergy to that particular food. Multiple foods can be tested in this manner simultaneously. A food challenge will often be done to confirm a food allergy as there can be false positives with both skin and blood tests. During a food challenge a small amount of the food is given orally in the closely monitored environment of the allergist’s office.

 

Help with Food Allergies

Dietitians often work alongside allergists to help patients learn which foods they must avoid and to find suitable alternatives. A dietitian can also help with food selection, label reading, navigating grocery stores and restaurant menus.

 

Keep in mind, diagnosis of a food allergy in young children doesn’t mean that your child will never be able to consume that food (or foods) again. The majority of children who are allergic to wheat, soy, cow’s milk, and eggs will outgrow these allergies. Approximately 20% of children who are allergic to peanuts will outgrow this allergy (3). Periodic retesting will tell you if the allergy has been outgrown.

 

For more information about food allergies visit the links below:

 

1.    Centers for Disease Control and Prevention. Food Allergy Among U.S. Children: Trends in Prevalence and Hospitalizations 2008. http://www.cdc.gov/nchs/data/databriefs/db10.htm

2.    American Academy of Allergy Asthma & Immunology. Atopic March 2013.http://www.aaaai.org/conditions-and-treatments/conditions-a-to-z-search/Atopic-March.aspx

3.    American Academy of Allergy Asthma & Immunology. Food Allergy 2013.http://www.aaaai.org/conditions-and-treatments/library/at-a-glance/food-allergy.aspx

Food Allergies 101

by Diana Chard, RD

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© 2018 by The Dietitians Network of Nova Scotia.