Food allergies are allergic reactions caused by ingestion of foods that contain allergenic protein components. The most common food allergies include: peanut, milk, soy, wheat, eggs, shellfish, fish, and nuts.
Allergic reactions can be life-threatening and immediate such as anaphylaxis due to peanuts, or they can be non-life-threatening resulting only in hives or eczema.
Laboratory blood testing can be very useful in diagnosing food allergies. Additional tests include skin prick testing, patch testing, or food challenge testing.