Since the beginning of the century when HAMBURGER, SCHLOSS MANN, and MORO first described food allergy in infants being fed with cow's milk, this topic has been the subject of very con troversial discussions among pediatricians. The dispute is illus trated by markedly fluctuating incidence figures, ranging from denial of the disease to incidence rates up to one in ten infants. The explanation for the differing incidence figures lies in the lack of a single laboratory test which is simple as well as applicable and reliable for all clinical and immunological reactions. Even though the classic allergic hypersensitivity reactions mediated by specific IgE antibodies are relatively clearly defined, there still exist other more complex immune responses which are more dif ficult to recognize. In the fall of 1987 internationally renowned experts from var ious fields met to define and discuss the fundamentals, organic manifestations, and the current status of diagnosis, treatment, and prevention of food allergy in childhood. The results have been collected in the volume in hand, in hopes that it will encourage more public involvement in the discussion of this illness, which is fortunately mostly transient.