Cincinnati Children's Blog

Food Allergy vs Intolerance: What’s the Difference?

Food Allergy vs Intolerance: What’s the Difference?
Your son has a peanut butter and jelly sandwich for lunch and 10 minutes later has hives around his mouth. Your daughter eats a bowl of ice cream and a couple hours later complains of a bellyache. Both scenarios can be reactions to foods – but are they allergies or intolerances?

This is a question that I answer frequently in our allergy clinic, and it’s important to understand the difference between the two. The terms intolerance and allergy are often used interchangeably, but they’re indeed quite different: one can cause mild to moderate symptoms, and the other can be potentially life-threatening.

Food Allergy
I find the easiest way to explain the difference between the two is to start with food allergy. Food allergies are defined as an immunologic (or immune system) response to eating a specific food. When the offending food is eaten, the body thinks that it is harmful and will produce antibodies called immunoglobulin E (IgE) to defend against it, producing an allergic reaction. The symptoms of an allergic reaction can range from mild to life-threatening and can occur anywhere on the body and happens fast, usually within 20 minutes. Additionally, when your child is allergic to a specific food, he will have a reaction every time he eats it, although the amount that will cause a reaction may vary, from a trace amount to a full serving.

Food Intolerance
On the other hand, food intolerance is a reaction that happens during the digestive process and is NOT life threatening. Common symptoms include gas, cramping and bloating. When your child has an intolerance to a particular food, it can take hours for her to notice symptoms as the food has to go through the digestive process before symptoms are felt. Typically there is a “tipping point” with food intolerance. Your child may be able to eat a little amount of the offending food without having symptoms; however, at some point she’ll start having symptoms if she eats it more frequently. For example, she might not be able to eat cheese with every meal, but she can have a small amount once a day.

Key differences between food allergy and intolerance:

[12px],[align-center;12px]Allergy,[align-center;12px]Shared Symptoms,[align-center;12px]Intolerance|[align-center;b;12px]

Symptoms,[12px]Rash and%2For hives

Itchy Skin

Shortness of breath

Trouble swallowing

Chest Pain

Sudden drop in BP

Is life threatening,[12px]Nausea


Vomiting,[12px]Gas, cramps, bloating




Is not life threatening|[align-center;b;12px]Timing of Symptoms,[12px]Quickly after eating the food,[12px],[12px]Can take hours|[align-center;b;12px]Frequency,[12px]Every time food is eaten

Only need to eat a little to have symptoms,[12px],[12px]May need to eat a lot of it
The bottom line is that food allergies need to be taken very seriously. If you suspect your child has a food allergy, start with your pediatrician. She may recommend your child be evaluated by an allergist. If your child has a known food allergy, please keep his injectable epinephrine with him at all times.

On the other hand, food intolerances, while not life threatening, can certainly cause discomfort. They can be difficult to recognize in children because you have to notice the pattern of symptoms and narrow down the offending food. The most common food intolerance is lactose intolerance, which is the body’s inability to digest the sugar found in milk. Fortunately there are lactose free milks that you can try. If you suspect your child has a food intolerance, please have a conversation with your pediatrician before altering his diet.

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