Gluten is a protein found in many different grains, including wheat, rye, oats and barley. Individuals who develop an allergy to gluten -- a condition called celiac disease -- are unable to consume foods containing this protein without enduring gastrointestinal pain, including diarrhea in some cases.

Some individuals may experience an allergic reaction to a specific type of food. Symptoms are generally mild. For others, however, reactions can be extreme and sometimes life threatening. Blueberries contain salicylates, which are natural-occurring chemicals in plants.

Dairy allergy symptoms in adults are less common than in children, but they have a tendency to be more persistent. Skin, respiratory and gastrointestinal symptoms may occur separately or they may overlap. In the most severe cases of dairy allergy, anaphylaxis is a life-threatening symptom.

Sulfites are used in the food industry to prevent oxidation and spoilage of food, preserve flavor, control bacterial growth and bleach food starches. Sulfites are metabolized by the enzyme sulfite oxidase.

According to the American Academy of Allergy, Asthma and Immunology, almost 15 percent of people in the United States experience some type of allergic reaction to pets such as cats or dogs. The primary cause of such allergies is pet dander—the dead skin cells cats and dogs shed on a daily basis.

Temporomandibular joint and muscle disorders involve the chewing muscles and joints connecting the lower jaw to the skull. Although TMJ is technically the abbreviation for the joint, people commonly use this term as shorthand for the disorders and symptoms, says MedlinePlus.

Gastritis, an inflammation or swelling of the stomach lining, can be a painful condition that is often caused by infection, drugs, stress or an autoimmune response. Treatment of gastritis is focused on treating the underlying cause and eliminating the irritant or offending substance.

Sulfa allergy is the allergic response that occurs from the presence of the compound structure SO2NH2. This compound can be found in the molecular makeup of many different drugs. The term "sulfa"

Gluten is a complex protein found in wheat, rye and barley. Gluten intolerance is a broad term that refers to different degrees of gluten sensitivity. Celiac disease is an autoimmune condition characterized by severe gluten intolerance.

Lactose intolerance is a common digestive problem that can result in a variety of uncomfortable, although short-lasting effects. However, these symptoms occur entirely in your digestive system. If you experience symptoms anywhere else in your body after drinking milk, you may have a milk allergy.

Allergies to the fungus Cladosporium can generate health symptoms all year long. Like some other molds, Cladosporium grows indoors and outdoors. According to the Mayo Clinic, its various strains are some of the most common allergenic mold species. Cladosporium growths appear green, brown or black.

People often cut sugar out of their diet when trying to lose weight, control diabetes or simply improve the quality of their food and beverage choices. Regardless of the reason, giving up sugar can be challenging. Also, the omission of sugar or other related diet changes may even be linked to headaches.