Do you have celiac disease or wheat allergy?

I have seen 5 patients in the past 2 weeks asking the question: "Do I have a wheat allergy or celiac disease?"

Both are immunologic diseases, but they are not the same and they can coexist. Wheat allergy is a classic food allergy caused in this case by the proteins in wheat. Typically, affected patients have symptoms of the gastrointestinal tract and sometimes with the skin and respiratory tract. Avoiding wheat is the only available therapy and this is very effective.

I am going to summarize briefly Celiac disease and provide some reliable links. Celiac disease is an immunologic reaction to the protein called gluten found in wheat and other closely related grasses, such as barley and rye. The reaction especially affects the small intestine and so can reduce the body's absorption of nutrients. Diagnosis is based on history, physical exam, labs, and biopsy. The only effective treatment is to strictly avoid foods containing gluten.
Overview: http://jama.ama-assn.org/cgi/content/full/293/19/2432, or
http://digestive.niddk.nih.gov/ddiseases/pubs/celiac/, or http://www.gi.org/patients/gihealth/celiac.asp.
Understanding labs used for diagnosis:
http://www.labtestsonline.org/understanding/analytes/celiac_disease/test.html. Dietary guide:
http://www.naspghan.org/user-assets/Documents/pdf/diseaseInfo/GlutenFreeDietGuide-E.pdf.
Support groups: http://www.csaceliacs.org/ and http://americanceliac.org/cd.htm.

In both cases, I recommend a diet that avoids at least all wheat products for at least one month plus keeping a very detailed food diary. This should list what the food and drinks were as well as where they came from. Often, patients discover that the cause is not wheat but something else, such as an additive, preservative, food dye, or excipient. Once known, these should be avoided. Balancing good nutrition versus avoiding triggering substances can be difficult. In some cases, I recommend speaking with a certified nutritionist. As part of a healthy lifestyle, I also recommend regular exercise.

If you have questions about wheat allergy or celiac disease, ask your doctor.