Allergy Testing
Allergy testing is often seen as being well proven, scientific and accurate. In contrast, food intolerance testing is seen as unscientific and unproven. But just how accurate is allergy testing?
Skin Prick Tests are performed to identify the causes of allergy but when compared to results from oral challenges there has always a great degree of inconsistency. Doctors have never been able to explain why this should be the case.
A study of skin prick testing by Kim et al goes a long way to answering this question.
Quite simply, the results from skin prick tests significantly improves when fresh food is used for the test rather than commercial allergen extracts.
The study focused on patients with atopic dermatitis and the allergens investigated were milk, egg white, egg yolk, and soya bean. What they found was that when you compare fresh food samples and commercial allergens they are DIFFERENT in structure. Most significantly some of the protein elements implicated in allergic reactions are missing in the commercial samples.
Before you rush of to your allergist and demand a different type of skin prick test it is worth noting that even though the fresh foods resulted in a greater degree of accuracy the percentages still did not reach the 70s. It would appear that oral food challenges and use of elimination diets are more accurate methods of testing.
You can find out about testing for food intolerance in The Food Intolerance Handbook.
Kim TE, Park SW, Noh GW, Lee SS.
Comparison of Skin Prick Test Results between Crude Allergen Extracts from Foods and Commercial Allergen Extracts in Atopic Dermatitis by Double-Blind Placebo-Controlled Food Challenge for Milk, Egg, and Soybean.
Yonsei Medical Journal 2002: 43(5); 613-620.
Comparison of Skin Prick Test Results between Crude Allergen Extracts from Foods and Commercial Allergen Extracts in Atopic Dermatitis by Double-Blind Placebo-Controlled Food Challenge for Milk, Egg, and Soybean.
Yonsei Medical Journal 2002: 43(5); 613-620.