1. Food Allergy Triggers & Where They Hide Slideshow Pictures
2. Take the Quiz on Allergies
3. 10 Common Allergy Triggers Slideshow Pictures

Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Food allergy facts
• Introduction to food allergies
• How do allergic reactions to food occur?
• What are the symptoms and signs of food allergy?
• Do infants and children have problems with food allergy?
• What are the most common food allergies?
• What is cross-reactivity?
• What is oral allergy syndrome?
• What is exercise-induced food allergy?
• What conditions have mistakenly been attributed to food allergy?
• What conditions mimic food allergy?
• How is food allergy diagnosed?
• What is the treatment for a food allergy?
• Are allergy shots effective for food allergy?
• Pictures of Food Allergy Triggers & Where They Hide - Slideshow
• Take the Quiz on Allergies
• Pictures of 10 Common Allergy Triggers - Slideshow
• Celiac Disease (Celiac Sprue) FAQs
• Patient Comments: Food Allergy - Allergy Shots
• Patient Comments: Food Allergy - Symptoms
• Patient Comments: Food Allergy - Describe Your Experience
• Find a local Asthma & Allergy Specialist in your town
• Food Allergy Index

The oral allergy syndrome is another type of cross-reactivity. This syndrome occurs in people who are highly sensitive, for example, to ragweed or birch pollen. During the seasons that these allergens pollinate, the affected individual may find that when he or she tries to eat fruits, chiefly melons and apples, a rapid onset of itching is experienced in the mouth and throat, and the fruit cannot be eaten. The oral allergy syndrome is also known as or pollen-food allergy syndrome and is thought to be a type of contact allergy related to the presence of proteins in certain foods that cross react with allergy-causing pollen proteins. Oral allergy syndrome occurs in up to 50% of those who have allergic rhinitis caused by pollen. Symptoms are immediate upon ingestion of fresh or uncooked foods and include the itching, irritation, and mild swelling of the lips, tongue, palate, and throat. Cooked fruits and vegetables usually do not cause the reaction. The symptoms usually go away within minutes, although up to 10% of people will develop systemic (body-wide) symptoms, and a small number (1%-2%) may experience anaphylactic shock. Tree nuts and peanuts tend to cause more severe reactions than other foods.

Exercise can induce an allergic reaction to food. The usual scenario is that of a person eating a specific food and then exercising. As he exercises and his body temperature increases, he begins to itch, gets lightheaded, and soon develops the characteristic allergic reactions of hives, asthma, abdominal symptoms, and even anaphylaxis. This condition has been referred to as food-dependent exercise-induced anaphylaxis (FDEIA) and is most common in teens and young adults. The cure, actually a preventive measure, for exercise-induced food allergy is simple -- not eating for at least two hours before exercising.