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

In adults, the most common foods that cause allergic reactions are shellfish, such as shrimp, crayfish, lobster, and crab; nuts from trees, such as walnuts; fish; eggs; and peanuts, a legume that is one of the chief foods that cause serious anaphylactic reactions. In highly allergic people, even minuscule amounts of a food allergen (for example, 1/44,000 of a peanut kernel) can evoke an allergic reaction. Less sensitive people, however, may be able to tolerate small amounts of a food to which they are allergic.

In children, the pattern is somewhat different from adults, and the most common foods that cause allergic reactions are eggs, milk, peanuts, and fruits, particularly tomatoes and strawberries. Children sometimes outgrow their allergies, but adults usually do not lose theirs. Also, children are more likely to outgrow allergies to cow's milk or soy formula than allergies to peanuts, fish, or shrimp. Adults and children tend to react to those foods they eat more often. For example, in Japan, allergy to rice, and in Scandinavia, allergy to codfish, is more common than elsewhere.

Cross-reactivity is the occurrence of allergic reactions to foods that are chemically or otherwise related to foods known to cause allergy in an individual. If someone has a life-threatening reaction to a certain food, the doctor will counsel that patient to avoid related foods, which also might induce the same reaction. For example, if a person has a history of a severe allergy to shrimp, he or she can also possibly be allergic to crab, lobster, and crayfish.