Can you tell if nausea after a food is a food allergy?

Skin testing: Skin testing can reveal a food allergy, but will be negative if the nausea represents an intolerance. If you're able to identify the food that is causing the nausea, there is no need for skin testing, because there is no specific treatment for specific food allergies. Whether the nausea represents a true allergy or an intolerance, the treatment is the same - just avoid the food.

Not usually.: While I have seen babies that vomit with egg or milk ingestion, the most common symptoms are swelling of the mouth/face, generalized hives or swelling, 15 minutes to 2 hours after ingestion. Cardio-respiratory symptoms are possible; gastro-intestinal symptoms are less common.

Depends: There are many causes of nausea after eating foods. If one is experiencing these problems see pcp for evaluation. If other causes are ruled out then food allergy evaluation may be appropriate.

Food allergies: Milk, eggs, wheat, soybeans, fish, crustacean shellfish, tree nuts ; peanuts cause 90 % of food allergic reactions. Up to 15 million americans suffer from food allergies ; need to avoid not only certain foods but any ingredient that contains proteins derived from them. In some cases, anaphylaxis can result. See http://www.Boston.Com/lifestyle/health/blog/nutrition/2013/11/the_dangers_of_dining_out.