According to the MayoClinic, food allergies affect 6 to 8 percent of children under 5 in the United States and 3 to 4 percent of adults. Food allergies can cause a range of symptoms from abdominal pain to hives.

For those with celiac disease and gluten intolerance, even a minute amount of gluten can present serious problems. While avoiding the obvious gluten-laden foods, such as bread and pasta, may be easy, it is more difficult to avoid drugs that may contain small amounts.

People with celiac disease must avoid gluten, which is the protein of wheat, rye, barley and some other grains. Gluten is found in many traditional snack foods, including some brands of crackers, chips, candy and baked goods.

Gas and bloating are possible symptoms of a food allergy, but there is no one food, or group of foods, that specifically causes those issues. However, symptoms of a food allergy can vary from person to person, so it's possible that gas and bloating are the only symptoms that you experience if you have a food allergy.

Peas are in the same food family as peanuts and may cause an allergic reaction in people with a peanut allergy, according to Allergic Child. A pea protein allergy is an adverse reaction of the immune system to the specific proteins found in peas.

Your diet provides the necessary building blocks for the body to produce energy and maintain good health. A good diet, therefore, is the foundation of good health. Your food choices can have a significant impact on how well your body functions.

Dairy intolerance and dairy allergy are two different things, according to the National Digestive Diseases Information Clearinghouse. Dairy or lactose intolerance is a reaction to the sugars in milk. Your body either lacks the enzyme, lactase, which breaks down lactose or your body does not produce enough.

Milk contains water, proteins, minerals, fats and carbohydrates (lactose is the milk sugar). Those who are allergic to milk have a reaction to the proteins, which in cow’s milk are whey found in the liquid portion and casein found in the solid or curd portion.

An allergy to eggs can cause a range of reactions, from a mild rash to severe breathing difficulty. Egg allergies often begin in infancy or early childhood. As you grow older, your body may adjust to the proteins in eggs that trigger allergies, and you may be able to enjoy these nutritious foods.

Sulfa drugs can cause allergic reactions in some people, including hives, swelling and difficulty breathing. If you've ever experienced a reaction to a sulfa drug, your doctor may have diagnosed you with a sulfa allergy.

Some people are unable to eat gluten, a protein found in barley, rye and wheat, without becoming sick. Gluten intolerance, known as celiac disease, is an autoimmune disorder that damages the digestive system. Intestinal bleeding has many causes and can be difficult to diagnose.

Hives or a rash are a common skim problem that can occur as a result of dry skin or a reaction to a food or medication. Although high doses of vitamin C don't usually cause these symptoms, a breakout of hives or a rash after taking a supplement or consuming a food with vitamin C may indicate an allergy.