Researchers estimate the number of people with food allergies in the U.S. to be 32 million. It breaks down to 6 million children and 26 million adults – more than previously thought.1
It is common for food allergies to develop in childhood, but you can develop a food allergy at any age. Adults are more likely to develop allergies to crustacean shellfish (like crabs, lobster or shrimp), peanuts, milk, tree nuts and fin fish.1 Adult-onset food allergies are generally life-long and are not “outgrown.”
What If You Suspect You Have a Food Allergy?
A food allergy is when your body’s immune system reacts to a food. This happens every time you eat the food. Symptoms can include any of the following:
- Skin rash, itching, hives
- Swelling of the lips, tongue or throat
- Shortness of breath, trouble breathing, wheezing
- Stomach pain, vomiting, diarrhea
- Feeling like something awful is about to happen
Food allergies and food intolerances are different. A food intolerance is usually a digestive issue. But a food allergy involves your immune system. These are managed differently, so it is important to get a correct diagnosis.
For example: Lactose intolerance is a common digestive problem when people lack a specific enzyme (lactase). This enzyme helps them digest lactose (a milk sugar). It can cause uncomfortable and painful symptoms like stomach cramps, nausea, bloating, gas and diarrhea. It can be managed by eating foods that do not contain lactose or by taking a lactase supplement to help with digestion.
Milk allergy, on the other hand, is an immune response to proteins found in milk. The symptoms can be life-threatening. To prevent a severe allergic reaction, people with a milk allergy must avoid ingesting milk. If a severe allergic reaction happens, the treatment is an injection of epinephrine followed by urgent medical care and possibly more medicines.
Keep notes or a journal about what happens when you eat a certain food. Share these notes with your doctor as they will become an important part of your medical history. You may need a referral to an allergist for diagnosis.
An allergist will use your medical history and some tests to see if your body is “sensitized” to a food. The tests alone cannot diagnose food allergy. There are two common food allergy tests that check to see if your body is making the antibody (immunoglobulin E, or IgE) responsible for allergy:
- A blood test known as the specific IgE allergy test
- A skin test known as skin prick test (SPT) and sometimes called a scratch or puncture test
But these tests can only show that the antibody exists (called “sensitization”). They don’t show how your body reacts to the food in question. Some people have the antibodies (are “sensitized” or have “elevated test results”) but they are not actually allergic and can eat the food without symptoms. This is why your medical history, or the experience you have when you eat foods, is also important.
The best test for food allergy is an oral food challenge. This is a controlled test that involves eating small amounts of the food under the supervision of an allergist over several hours to see if you develop symptoms.
What Do You Do If You Are Diagnosed With a Food Allergy?
- You need to know exactly which foods you are allergic to and what you need to avoid. Most foods are required by the FDA to label the eight most common food allergens in plain language in the ingredients. But this doesn’t apply to foods you order in a restaurant, so it is important to understand the various names of your allergen.
The FDA requires food manufacturers to label these major food allergens in plain language:
- Tree nuts
- Crustacean shellfish
- You need to read labels every time. Ingredients can and do change. Read the entire ingredients list to look for your food allergen.
- If you are dining out, ask the manager or server to check ingredients. Ask that your food be prepared carefully to avoid contact with your allergen.
- You will also need self-injectable epinephrine so you can treat a severe allergic reaction if one occurs. A severe allergic reaction is also known as anaphylaxis. Ask for an emergency anaphylaxis action plan from your doctor to help you to know when you should use the epinephrine. Always carry two epinephrine auto-injectors.
- Teach your loved ones about your condition. If you have a significant other, it’s important to talk to them about your allergy. Talk to them about meal preparation, reading labels, cross-contamination and even kissing. If your loved one eats your allergens, you’ll need to create a system at home to prevent contact with your food.
- Gupta, R. S., Warren, C. M., Smith, B. M., Jiang, J., Blumenstock, J. A., Davis, M. M., … Nadeau, K. C. (2019). Prevalence and Severity of Food Allergies Among US Adults. JAMA Network Open, 2(1). doi: 10.1001/jamanetworkopen.2018.5630
Melanie Carver is the Vice President of Community Health and Services at the Asthma and Allergy Foundation of America. She leads the organization’s digital health communications and community building to support and educate people with allergies and asthma to empower them to improve their health.