Identifying Food Allergy Symptoms

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Symptoms of a food allergy vary and range from mild symptoms like a few hives and mild digestive discomfort to severe anaphylactic symptoms of swelling of the tongue and lips and difficulty breathing, which can be life-threatening.

Food allergy symptoms occur when a person has an immune response to a substance in food (usually a protein). The body identifies the substance as foreign and produces natural defenses that overreact to its exposure to defend against it.

This article will cover mild to severe food allergy symptoms and how to handle them, the duration of symptoms, and treatment options.

An illustration with information about mild food allergy symptoms

Illustration by Zoe Hansen for Verywell Health

Mild Food Allergy Symptoms to Recognize

A mild symptom typically impacts one part of the body. Some common yet mild food allergy symptoms can affect your nose, mouth, skin, and gut:

  • Nose: Itchy or runny nose, sneezing
  • Mouth: Itchy mouth, scratchy throat
  • Skin: A few hives, mild itch (note the word few, many hives can indicate something more serious/severe)
  • Gut: Mild nausea, discomfort, or stomach cramps

Most Common Food Allergens

For most people, the first symptom of a food allergy reaction occurs between two minutes and two hours of ingestion. This is a wide range of time, therefore, it is important to be able to identify symptoms.

Your symptoms are unique; reactions among people can be different and can be influenced by the type of food you are allergic to, how severe the allergy is, and the quantity eaten. Even if you've safely eaten a food for years, you can develop an allergy to it later in life.

Food Allergy vs. Food Intolerance/Sensitivity

A very important distinction to make is that food allergies are different from food sensitivities or intolerances. Food allergies are an immune system reaction to specific allergens (substances) in food or drink.

Food sensitivities or intolerance occur in the digestive system because of enzyme deficiencies (such as with lactose intolerance), sensitivity to food additives, or reactions to naturally occurring chemicals in foods.

Severe Food Allergy Symptoms: What to Do 

Severe food allergy symptoms usually come on rapidly and can progress to anaphylaxis. A severe reaction may affect multiple parts of the body and must be treated with epinephrine.

Epinephrine is a hormone used to treat anaphylaxis and is delivered via an EpiPen. It works quickly to reverse severe symptoms, but the person must be immediately transported to an emergency room for further evaluation. Delayed or improper treatment of anaphylaxis can be fatal.

Severe symptoms include:

  • Mouth: Significant and rapid swelling of the tongue or lips
  • Eyes: Itching, redness, tearing, swelling
  • Skin: Many hives over the body, widespread redness, swelling under the skin, eczema flare up
  • Gut: Repetitive vomiting or severe diarrhea
  • Throat: Tightness, hoarse voice, difficulty breathing and swallowing, or feeling like your throat is closing up
  • Lung: Wheezing, shortness of breath, repetitive cough
  • Heart: A drop in blood pressure, paleness or blue, faint, weak pulse, dizzy
  • Psychological: Anxiety, confusion, loss of consciousness, worried that something bad is going to happen

Anaphylaxis Risk

People who have had a previous anaphylaxis reaction are at increased risk. In addition, people with allergies or asthma and those with a family history are also at higher risk.

How Long Do Food Allergy Symptoms Last?

Allergic reactions can last for varying amounts of time. Symptoms may start right after eating food or hours later. In certain instances, particularly after a severe reaction, people are at risk of having biphasic reaction.

A biphasic reaction causes a second wave of symptoms to occur one to four hours later or sometimes even longer. This is one of the reasons people who have had a severe reaction are monitored in the hospital for four to six hours after the initial occurrence.

Comparing Treatment Options for Food Allergy Symptoms

If you have been diagnosed with a food allergy, your allergist should have provided you with an individualized treatment plan, called a Food Allergy & Anaphylaxis Emergency Care Plan. The plan outlines the protocol you should follow if you have a food allergy reaction.

Symptoms and treatment recommendations are listed for mild and severe reactions. For example, if you have a mild reaction (such as an itchy throat or a few hives), then treatment may require an antihistamine (like Benadryl) and close monitoring.

Symptom that affect one or more body part or a mild reaction that includes more than one body system will require epinephrine. After you've given a dose of epinephrine to yourself or your child, call 911 or go to the emergency room for observation. Epinephrine lasts around 30 minutes, and sometimes people need a second dose.

The Food Allergy plan should be signed by a healthcare provider and distributed to people who care for your children, such as school nurses, camp counselors, coaches, family members, and babysitters.

If you haven't seen an allergist or built a care plan, it's important to do so. Food allergies can cause serious consequences if they are not treated quickly and correctly.

Being Mindful of Food Allergy Symptoms

Food allergy reactions may differ each time you eat the food you're allergic to. The American College of Allergy, Asthma, and Immunology cautions that just because an initial reaction causes minor symptoms doesn't mean all reactions will be the same. The next time you eat the same food, you may experience severe symptoms.

Knowing how to avoid the foods you or your child are allergic to is important when grocery shopping or dining out.

You'll also always want to carry your EpiPen and other recommended medications and have access to your care plan. If you have a reaction away from home, you want to be able to treat it properly and promptly.

At the Grocery Store

When shopping for groceries, make sure you are reading food labels and ingredients lists. If the market offers food samples, ask how the food was prepared or read the label before tasting them. Products that contain your allergen will need to be avoided.

If you are unsure of an ingredient, you can call the food manufacturer.

Dining Out

Dining out with allergies can take extra planning, especially if your allergies are severe, but it is not impossible. Ask your server if meals are prepared with ingredients you are allergic to—even in foods you would not suspect. If the meal you are considering ordering contains an ingredient you're allergic to, ask if it can be made without that ingredient or if a substitution is possible.

Make sure that there is no risk of cross-contamination. For example, if your meal was prepared or cooked at a station that preps or cooks the food you are allergic to, then it could contaminate your food. Don't be afraid to ask specific questions or to send back food that looks suspicious.

Summary

Food allergy symptoms can present differently in children and adults. The severity of your symptoms will dictate your treatment method. If you suspect that you or your child has food allergies, it is important to see an allergist so that you can receive the proper diagnosis and treatment.

Having food allergies doesn't mean you cannot dine out or shop safely. A little extra research and preparation can allow you to enjoy social engagements. Make sure you always carry your treatment care plan along with your medication. In the instance that you do ingest something you are allergic to, you will want to be able to treat it quickly and safely to avoid a serious reaction.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American College of Asthma, Allergy, and Immunology. Food allergy.

  2. Food Allergy and Research Education. Recognizing and treating symptoms.

  3. Food and Drug Administration. Food allergies: what you need to know.

  4. American Academy of Allergy, Asthma, and Immunology. Food intolerance versus food allergy.

  5. American Academy of Allergy, Asthma, and Immunology. Anaphylaxis.

  6. Food Allergy Research and Education. Biphasic reactions are more likely when symptoms of initial reaction are severe.

  7. Food Allergy and Research Foundation. Food allergy and anaphylaxis emergency care plan.

  8. Allergy and Asthma Network. What is epinephrine?

By Barbie Cervoni, RD
Barbie Cervoni MS, RD, CDCES, CDN, is a New York-based registered dietitian and certified diabetes care and education specialist.