Common Food Allergies and Symptoms
Food allergies occur when your immune system responds to a specific food. The response can cause symptoms that vary from mild to severe. Common food allergens are nuts, dairy, fish, and wheat.
Your immune system is a complex system of cells and chemicals that protects your body from pathogens and other threats. Antigens are small markers on the surface of pathogens and other cellular and noncellular particles. The immune system can recognize these antigens and produce an immune response.
If the immune system responds to an antigen on the surface of a food or other non-threatening substance, it is called an allergy. IgE is a specific class of antibodies that is involved in allergic reactions. Allergy testing for food allergies involves measuring IgE antibodies for specific foods.
Food intolerances are symptoms that you may experience after consuming certain foods, but they do not involve the immune system.
How Common Are Food Allergies?
According to Food Allergy Research & Education, approximately 32 million Americans have food allergies, which is about 1 in 10 adults and 1 in 13 children. About 30,000 people each year require emergency treatment for food allergies, and 150 die from an allergic reaction to food.
In one survey, at least 10.8% of U.S. adults had food allergies, and 19% believed they had a food allergy. Shellfish allergy was the most enduring, affecting 2-3% of adults.1
Foods That Cause Allergies
Most children with food allergies outgrow them during adolescence or adulthood. However, some persist.2 The most common allergens that persist into adulthood include the following:1
- Shellfish (2.9% of adults)
- Peanut (1.8% of adults)
- Milk (1.9% of adults)
- Tree nut (1.2% of adults)
- Fin fish (0.9% of adults)
Other common food allergies include:1
- Tree nuts
While any food could cause an IgE-mediated food allergy, fish/seafood and peanuts/tree nuts account for the most reaction in adults.2
Oral-allergy syndrome, or pollen-food syndrome, affects as much as 5% of the population. It is a milder food allergy that causes symptoms when raw fruits and vegetables or nuts come into contact with the mouth and throat. Most people experience itchiness and mild swelling in the mouth and throat within a few minutes of consuming these foods.3
These reactions do not progress to a systemic reaction. Cooked foods do not typically cause these symptoms because cooking disrupts bonds in the marker the immune system uses to identify the food as an allergen.2
An uncommon food allergy requires a combination of exercise and ingestion of the suspected food.
- If you eat the food without exercising, no symptoms develop.
- If you exercise first, followed by eating the food, you will not experience these symptoms.
- A required pattern of food consumption first, followed by exercise within a few hours, makes identifying this type of food allergy difficult.2
Signs of Food Allergies
Symptoms of food allergies are typically local symptoms that are classified as mild and more systemic symptoms that are severe. Severe allergy symptoms can be life-threatening and require emergency treatment. Mild symptoms in more than one body part are systemic and, therefore, classified as severe. The severity of an allergic reaction depends on several factors, including how much of the food you ate and whether it was cooked, raw, or processed.3
Localized or mild symptoms of food allergies include:3
- Itchy mouth or throat
- A mild, localized skin rash such as hives or eczema
- Swelling beneath the skin
- Nausea or mild gastrointestinal symptoms
- Itchy, red, tearing eyes
- Nasal congestion
- Dry cough
Systemic symptoms are classified as severe and may include:3
- Shortness of breath
- Throat swelling
- Widespread skin rash
- Feelings of impending doom
What To Do if Symptoms Occur
Food allergies that affect the lungs, mouth, or throat are very serious as they can progress quickly and impact your ability to breathe. This risk is higher in people who have food allergies and asthma.3
Anaphylaxis is a severe allergic reaction to food that involves more than one body system. You may have a skin rash, wheezing, chest tightness, trouble breathing, or facial or airway swelling. Follow your doctor’s instructions for using an EpiPen and seek emergency help.
If you experience mild-to-moderate allergy symptoms, see an online doctor to discuss your symptoms and get symptomatic care. However, emergency care is needed if you have an allergic reaction.
How To Manage Food Allergies
Avoidance is the key to managing food allergies. However, this can be hard to do. Many people are unable to identify their exact triggers. Short of allergy testing, one step you can take is to keep a food diary. Record what you ate and any symptoms you experienced within a few hours of eating the food.
Once you identify potential food triggers, check food labels and ask questions at restaurants you visit. The Food Allergy Labeling and Consumer Protection Act of 2004 mandates that food manufacturers prominently indicate if the eight most common allergens are found in their products.4
Tell everyone about your food allergy and ask for help to avoid cross-contamination. Keep your food separate if necessary and prepare your food with separate utensils.
Antihistamines, both over-the-counter and prescription, can help treat allergy symptoms. If you have severe symptoms, talk to your doctor about getting a prescription for an EpiPen. Make an appointment with an online doctor and experience the benefits of telemedicine.
If your doctor writes an online prescription medication at the end of your visit, it can be filled by a partner pharmacy and shipped to you or sent to your local pharmacy.
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
1. Gupta RS, Warren CM, Smith BM, et al. Prevalence and Severity of Food Allergies Among US Adults. JAMA Network Open. 2019;2(1):e185630-e185630. doi:10.1001/jamanetworkopen.2018.5630
2. Iweala OI, Choudhary SK, Commins SP. Food Allergy. Current Gastroenterology Reports. 2018;20(5)doi:10.1007/s11894-018-0624-y
3. Boyce JA AaA, Burks AW, et al. Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel. Journal of Allergy and Clinical Immunology. 2010;126(6):S1-S58. doi:10.1016/j.jaci.2010.10.007
4. Dahl, R. . Food Safety: Allergen Labeling Takes Effect. Environmental Health Perspectives. 2006;114(1):A24-A24. doi:doi:10.1289/ehp.114-a24