The article you cite has not a double blind experiment:
> The parents and teachers who filled in the questionnaires could not be blinded as they had to supervise the food intake of the child and knew whether the child was following an elimination diet.
Do you have a reference of a similar article with a double blind test?
> The parents and teachers who filled in the questionnaires could not be blinded as they had to supervise the food intake of the child and knew whether the child was following an elimination diet.
Do you have a reference of a similar article with a double blind test?
Another question: Pears, apples and quinces are very related plants. Why pears are safe and apple not? http://en.wikipedia.org/wiki/Malinae