Standardized extracts, foods.

While progress has been made in the areas of food allergen characterization, both the complexity of the biochemical constituents of food and the body's normal physiologic (digestion) and immunologic responses to food ingestion provide challenging obstacles to efforts aimed at developing standardized food extracts. As indicated above, while currently available food extracts can be useful in the evaluation of food hypersensitivity, the results obtained using these reagents are far from optimal. Indeed, in some cases, skin testing after rubbing a small amount of the food on the skin may be more inciteful than using commercially prepared extracts. While this approach may provide physicians with help in terms of diagnosis, purified food components will be necessary to comprehensively study the complex issues of food allergen digestion and absorption; immune response and tolerance to food allergens; and hopefully, treatment and prevention of food hypersensitivity.