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What are hives?
Hives are small, red, raised bumps that appear on your skin. They are brought on by something that triggers your immune system to release chemicals called histamines. Certain foods are a common trigger of hives, affecting 4%–6% of children and 4% of adults.
Symptoms
If you have a food allergy, you will usually start to notice an allergic reaction like hives within a few minutes of eating the food. Sometimes, it can take up to two hours for symptoms to start. The reaction will probably go away within six hours.
Hives from a food allergy can look like individual raised bumps or can join together into a larger raised patch. They can be in a small area or all over the body. They tend to look like bug bites: pink bumps with paler centers. They also tend to itch, sting, or burn.
Sometimes a food allergy can also cause other symptoms, like swelling of the face, itchy mouth, coughing, runny nose, and vomiting or diarrhea. They might also be quickly followed by a more serious reaction, called anaphylaxis. This life-threatening condition, which makes it difficult to breathe or swallow, usually comes on fast, within 10–20 minutes of eating. You should call 911 if you’re experiencing these symptoms and use an Epi-Pen (epinephrine) if you have been prescribed one.
Why do foods cause hives?
When your immune system thinks something in a specific food is a danger to your body, it triggers a response. In most cases, it’s a protein in the food that the body thinks is harmful. The response can affect the respiratory tract, cardiovascular system, gastrointestinal tract, and skin.
Hives are the most common symptom of a food allergy. That’s because your skin contains something called mast cells, which are part of the immune system. When the mast cells become active, they release histamine, which causes hives to form.
Are children more likely to get hives?
Food allergies are more common in children and babies than they are in adults. The three most common foods that cause allergies in babies are cow’s milk, soy milk, and eggs. In older children, the most common allergens are peanuts, tree nuts, fish, shellfish, and wheat. Some food allergies tend to be outgrown, like cow’s milk, soy milk, and egg, but others like peanuts and tree nuts tend to be more permanent.
Foods that cause hives
While there are more than 170 foods that can cause a food allergy, 90% of all cases are triggered by eight foods. Companies are required by law to clearly show on the label if a food item contains any of these potential allergens. If you have an allergy, be sure to discuss your level of risk with your healthcare provider. Some people may be able to consume an allergen if it’s cooked or baked, but others may not.
Milk
If you have a milk allergy, you also need to avoid other dairy foods, like butter, cheese, ice cream, and yogurt. And because cow’s milk proteins are similar to those found in milk from other animals like goats and buffalo, you need to be careful when eating foods with those proteins. You may be able to eat foods containing milk if it’s been baked, like in a cake, but talk to your medical provider about your own risk.
Eggs
If you have an allergy to eggs, both the whites and yolks should be avoided, along with foods made with eggs like mayonnaise, pancakes, and some salad dressings. Similar to milk, baking eggs into a cake or cookies can disrupt the protein, making it less likely to cause an allergy. But discuss your personal risks with your medical provider.
Fish
While any fish could cause an allergy, salmon, tuna, catfish, and cod are common culprits. Fish can be an ingredient in unexpected foods, like Caesar dressing, barbecue sauce, Worcestershire sauce, and kimchi, so make sure to check ingredient lists.
Shellfish
There are actually two kinds of shellfish: crustaceans like shrimp, crab, and lobster, and mollusks, like clams, oysters, and mussels. Crustacean allergies are more common, with shrimp being the top allergen. But your allergist may recommend avoiding all shellfish just to be safe
Peanuts
Peanuts are actually legumes, not nuts, and they are the most common causes of anaphylaxis from food. So while in some people the allergy may cause hives alone, in others it can be combined with throat swelling that makes it difficult to breathe. Many different cuisines use peanuts in their foods, so be sure to mention your allergy before ordering at a restaurant. If you have a peanut allergy, your healthcare provider will likely prescribe epinephrine (an EpiPen) to use in emergencies.
Tree nuts
While there are 18 different types of tree nuts, the top allergens are walnuts, almonds, hazelnuts, pecans, cashew, and pistachio. Being allergic to one tree nut makes it more likely that you’re allergic to another, so your provider may recommend avoiding all of them. In addition to foods, tree nut oils can be found in lotions and soaps, so double check before buying a new skin product.
Wheat
A true allergy to wheat is different from Celiac disease, which is an issue with digesting gluten (something found in wheat). With a wheat allergy, you’ll want to steer clear of breads, cereals, pastas, and other foods made from wheat or wheat flour. It can be found in many foods so be sure to read the ingredients carefully. Wheat can be hard to avoid, but there are many wheat-free grains, like barley, corn, oat, quinoa, and rice, that you can eat instead.
Soy
If you’re allergic to soy, you need to avoid whole soybeans (called edamame), tofu, miso, and soy sauce. Soy protein is a common ingredient that can show up in everything from energy bars to canned soup.
Treatment
If you have food allergies that cause hives, the first recommendation is to avoid the food whenever possible. That means carefully checking ingredient labels and telling your waiter at a restaurant about your allergy. If you do eat something that causes hives and the itch is extreme, taking a cool bath or an antihistamine like Benadryl can help you feel better.
If you start to have signs of anaphylaxis, like trouble breathing or swallowing, go to the ER immediately or call 911 because that’s a life-threatening situation. And make sure to keep epinephrine (an Epi-Pen) nearby at all times. This injection can save your life if you ever have anaphylaxis.
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