Food allergies happen when the body’s immune system mistakes a food for something bad and attacks it. This causes symptoms of an allergic reaction, which can be life-threatening. Symptoms can appear within minutes after eating the food or delayed for up to 2 hours after eating.

Food Intolerance

Food intolerance is not the same thing as a food allergy. It does not involve the immune system and is not life-threatening. A common example is lactose intolerance (trouble digesting milk sugar).

Mild Symptoms

Mild symptoms may include:

  • Red, itchy skin (hives)

  • Upset stomach

  • Tingling or itching of the mouth and lips

  • Stuffy, itchy nose, sneezing (rare)

  • Red, itchy, watery eyes (rare)

Treating Mild Symptoms

Mild symptoms should be treated with an antihistamine, such as diphenhydramine (Benadryl®) or cetirizine (Zyrtec®) as soon as you can.


Anaphylaxis (an-a-fl-LAK-sis) is a more serious and severe allergic reaction. It starts quickly and can cause death.

Severe Symptoms

More severe symptoms include:

  • Vomiting, stomach pain, diarrhea (loose stools)

  • Hoarse voice, tight throat or feeling like there is a lump in your throat

  • Wheezing, chest tightness or trouble breathing

  • Hives or drooling in younger children

  • The feeling that something bad is happening

  • Fainting

Treating Severe Symptoms

Severe symptoms are treated with a shot of epinephrine or an EpiPen®. If an EpiPen® is used, the person must be taken to the nearest emergency room or call 911.

How a Food Allergy Is Diagnosed

A doctor will review the history of symptoms and may do allergy testing. The doctor may diagnose a food allergy if there is a history of having a reaction when eating a certain food and there is a positive allergy test result.

Allergy history:

At your visit, you may be asked:

  • Which foods were eaten?

  • What were the symptoms after eating the food?

  • How soon after eating the food did the symptoms start?

  • How long did the symptoms last?

  • How were the symptoms treated?

  • Has this happened before?

  • What happened other times this food was eaten?

Allergy testing:

Tests may involve a skin prick or blood test. The skin prick test can be done in the clinic. Results are ready within 15 minutes. The blood test measures the level of the allergic protein or IgE. Blood test results take longer (about 1 week).

Food Labeling Laws

By law, food manufacturers must label major top 8 allergens. Food labels must show the major allergen in a “contains” statement or in the ingredient list of the food. Sesame is now the 9th major allergen and must be added to labels by January 1, 2023. The top major allergens include:

  • Milk

  • Soy

  • Peanuts

  • Tree nuts

  • Egg

  • Soy

  • Wheat

  • Fish

  • Sesame (1/1/2023)

  • Shellfish

“May Contain” Allergen Labels

Some labels may include "may contain" or "made on shared equipment" statements. These statements are not required by law. Random tests of products with these labels have found results that range from “none” to “higher amounts” that could cause an allergic reaction. We suggest that you avoid these foods.


Cross-contamination happens when other food(s) may come in contact with a food allergen or any food you need to avoid. This can be a problem for people with food allergies.

Dining Out

It can be stressful to dine out when you have a food allergy. Call ahead or eat at places that cater to food allergies. Some larger and chain restaurants train their staff how to handle food safely. They may also offer a lot of safe food options. There are phone apps such as Spokin and Allergy Eats that can suggest safe places to eat.

Common Questions

Will introducing my child to peanuts early prevent a peanut allergy?

In some cases, yes. In high-risk infants, early introduction of peanuts may prevent peanut allergy. Contact your allergist with questions about this.

Will avoiding foods during pregnancy that I’m allergic to prevent my child from having food allergies?

No. Not eating foods you are allergic to while pregnant or breastfeeding will not prevent your child from having food allergies.

Will waiting longer than 4 to 6 months to start solid foods prevent food allergies?

No. Waiting longer than 4 to 6 months of age to start solid foods will not prevent food allergies. Infants should begin with solid foods like fruits and vegetables. Then, parents can begin giving all foods, waiting a few days in between each new food to make sure they are tolerating the food. This includes foods that contain milk protein like yogurt, eggs, peanut, tree nuts, soy or wheat.

Will using soy milk formula instead of cow’s milk for infants prevent food allergies?

No, using soy milk formula will not prevent food allergies.

Are there medicines or treatments to cure food allergies?

No. There is no treatment for an existing allergy. The only way to prevent a reaction is to avoid the food you are allergic to.

Helpful Websites

Food Allergy Research and Education (FARE)
This provides information for schools, daycares, webinars for parents, research, and traveling.

Kids with Food Allergies -
This is great for those with a new allergy. It has great recipes, webinars and other information.

American Academy of Allergy, Asthma and Immunology (AAAAI)

Food Allergy Counselor
This is a great website to learn about strategies, support and behavioral health.

Medical Alert

Nuts Without Cross Contamination

Always read labels first as things may change.

  • Almonds - Barney Butter, Wonderful Brand Almonds(pistachios are made in a separate facility)

  • Cashews - Sunshine Nut Company

  • Pistachios - Wonderful Brand(almonds are made in a separate facility)

  • Walnuts - Daniel’s Farm and Derby Walnuts

  • Hazelnut - Nutella (contains milk)

  • Pecans - Pearson Farm

  • Peanut Butter - Skippy, Jif, Santa Cruz Organic, Smucker’s, Trader Joe’s