Food allergy: lessons from the past.

Because finite studies are customarily published as the observations are completed, general principles and unifying concepts may be difficult to discern. When the contributions to a field of study are viewed in retrospect and in their entirety, the concepts and common understanding that influenced the kind of observations made and the interpretations of the findings may be more apparent. Periodic attempts to identify obstacles to scientific progress in the past should serve to lessen the clutter in the path of further advancement of knowledge. The need for this exercise in the field of food allergy has been urgent, and this is an effort to that end.