Updated 18 May 2017

5 common hidden food allergens

Food allergies can be dangerous, here are the top five most common hidden food allergens and how to spot them.


Foods which cause allergic reactions are allergens, and they range from mild to severe, although all allergic symptoms should be taken very seriously.

Symptoms of a food allergy vary and can affect the skin, the gastrointestinal tract, the respiratory tract, and even the cardiovascular system. Typically symptoms appear within minutes of eating the offending food, but sometimes it can take several hours.

Mild symptoms may include hives, eczema, a redness of the face or eyes, an itchy mouth or ear canal, nausea or vomiting, diarrhoea and stomach pain. However symptoms can be severe, such as respiratory distress.

The top five common food allergens include:

- Peanuts

- Eggs

- Dairy

- Wheat

- Soy

Common hidden food allergens

However, while avoiding eggs or dairy might seem simple enough at first, it can be a minefield avoiding your food allergen if you eat out or eat processed foods.

Here are the most common ways the top five food allergens can be hidden in everyday foods:

Peanuts: Ingredients that may contain peanuts and should be avoided by those suffering from a peanut allergy include salad dressings, nougat and marzipan.

Eggs: It is the whites of the egg which contain the allergy-causing proteins. Egg protein can often be ‘hidden’ in foods such as baked goods, vaccines, mayonnaise and meringues.

Dairy: An allergy to dairy is very different from being lactose intolerant as it involves the immune system which reacts adversely to a protein in the milk. Foods to watch out for include custards, ghee and whey. It is a very common allergy and while it might appear to be easy to avoid dairy, it can still be found in foods such as coffee creamers, gravies and peanut butter, all of which may use some form of milk solids. Caseinate is also a form of dairy found in products such as canned tuna fish, dental chewing gums and even breath mints.

Wheat: Avoiding wheat can prove very challenging asthere are so many products which use it as a binding or thickening agent. It is different from a gluten allergy, but can be very severe in some cases. Foods to avoid which may contain wheat include cereal extract, couscous, ice-cream, ready-made burgers, beer and soy sauce.

Soy: Soybeans are used in most processed foods, which means it is hidden in virtually everything. These are the most common foods it is hidden in; Miso, Tofu, vegetable broth, some peanut butters and canned soups.

How to avoid hidden food allergens

If you have a food allergy, it’s vital to read all food product labels carefully and make sure you understand the various names certain allergens can hide behind. If you’re ever in doubt, rather call the manufacturer before you consume it to be sure.

- Print out a list of all potential food allergens and the various names they’re hidden under and take it with to the shops to cross-check ingredients lists.

- Cook with fresh ingredients.

- Avoid all processed food.

Read more

8 allergy myths

5 foods that reduce allergy symptoms

Understanding food allergies


Healthline: The most common food allergens; FARE: All about food allergies ; Kids With Food Allergy: What is a food allergy?


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Dr Morris is the Principal Allergist at the Cape Town and Johannesburg Allergy Clinics with postgraduate diplomas in Allergology, Dermatology, Paediatrics and Family Medicine dealing with both adult and childhood allergies.

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