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 complex process of digestion affects the timing, location, and particular symptoms of an allergic reaction to food. All of the symptoms of food allergy occur within a few minutes to an hour of eating. A food allergy can initially be experienced as an itching in the mouth and difficulty swallowing and breathing. Then, during digestion of the food in the stomach and intestines, symptoms such as nausea, vomiting, diarrhea, and abdominal pain can start. Incidentally, the gastrointestinal symptoms of food allergy are those that are most often confused with the symptoms of different types of food intolerance.

As mentioned previously, the allergens are absorbed and enter the bloodstream. When they reach the skin, allergens can induce hives or eczema, and when they reach the airways, they can cause asthma. As the allergens travel through the blood vessels, they can cause lightheadedness, weakness, and anaphylaxis, which is a sudden drop in blood pressure. Anaphylactic reactions are severe even when they start off with mild symptoms, such as a tingling in the mouth and throat or discomfort in the abdomen. They can be fatal if not treated quickly.