[Diagnostic and therapeutic procedure for two popular but quite distinct adverse reactions to food - fructose malabsorption and histamine intolerance].

Claiming to suffer from adverse food reactions is popular. In contrast to the classical food allergy, there are some pathomechanisms which are evidently dose-dependent. Thus the procedure in diagnosis and therapy must undoubtedly differ from the practice when food allergy is suspected or proven. Nevertheless many patients suffering from dose-dependent adverse reactions to food are given strict elimination diets, which is neither necessary nor helpful and decreases their quality of life broadly. This holds especially true for fructose malabsorption and histamine intolerance. For the latter, the term adverse reaction to ingested histamine is preferred, because histamine intolerance implies that symptoms are caused entirely by an enzyme defect. Why this is not very likely to be the only reason is discussed in this article. Both adverse reactions require an individual approach especially with regard to nutrition therapy. Therefore the task of diagnosis should be to establish an individual profile of tolerated and not tolerated foods taking into account that tolerance can greatly vary by meal composition, frequency and individual triggering factors. In view of this, therapeutic recommendations should not be based on the absolute quantities of the eliciting substance to be eliminated but on a feasible transfer into daily life. Thereby food restriction can be minimized and a high quality of life will be maintained.