• Some common foods that cause intolerance or allergy are dairy, eggs, wheat, soy, peanuts, tree nuts, fish and shellfish. However, any food can potentially trigger a reaction in some people.
• Dairy: Some people have trouble digesting lactose, a sugar found in milk and dairy products. This is called lactose intolerance and can cause symptoms like diarrhea, bloating, gas and nausea. Other people may have a true allergy to milk proteins, such as casein or whey. This can cause symptoms like hives, swelling, vomiting, wheezing and anaphylaxis.
• Eggs: Eggs are one of the most common food allergens, especially among children. Some people are allergic to the egg white, some to the egg yolk and some to both. Egg allergy can cause symptoms like skin rashes, nasal congestion, abdominal pain and anaphylaxis.
• Wheat: Wheat allergy is different from celiac disease or gluten intolerance. Wheat allergy is an immune reaction to any of the hundreds of proteins in wheat. It can cause symptoms like swelling, itching, hives, difficulty breathing and anaphylaxis. Celiac disease is an autoimmune disorder that damages the small intestine when gluten (a protein found in wheat and other grains) is consumed. It can cause symptoms like diarrhea, weight loss, anemia and osteoporosis. Gluten intolerance is a non-immune reaction to gluten that can cause symptoms like bloating, gas, fatigue and headache.
• Soy: Soy allergy is more common in infants and children than in adults. It can cause symptoms like hives, itching, swelling, wheezing, vomiting and anaphylaxis. Soy intolerance is a non-immune reaction to soy that can cause symptoms like diarrhea, nausea and abdominal pain.
• Peanuts: Peanuts are one of the most common and severe food allergens. They can cause symptoms like skin reactions, swelling, tingling in the mouth, shortness of breath and anaphylaxis. Peanut allergy can be life-threatening and requires strict avoidance of peanuts and peanut products.
• Tree nuts: Tree nuts include almonds, walnuts, cashews, pistachios and others. They can cause similar symptoms as peanut allergy, such as skin reactions, swelling, breathing problems and anaphylaxis.
Some people may be allergic to one or more types of tree nuts.
• Fish: Fish allergy can affect people of any age. It can cause symptoms like hives, swelling, nausea, vomiting, diarrhea
and anaphylaxis. Some people may be allergic to one or more types of fish.
• Shellfish: Shellfish allergy can also affect people of any age. It can cause symptoms like hives, swelling, wheezing, dizziness and anaphylaxis. Some people may be allergic to one or more types of shellfish, such as shrimp, crab, lobster or oysters.