"Histamine intolerance" is often based on a self-diagnosis. Due to the known range of reactions that can be mediated by the messenger substance histamine, it is postulated that food histamine can trigger the same reactions. Results of studies with double-blind, placebo-controlled oral provocation tests do not confirm this, but rather show that orally administered histamine does not trigger reproducible reactions and that symptoms often occur after placebo, indicating a strong nocebo effect. Without reproducibility, however, the definition for an adverse reaction to food is not fulfilled. As many sufferers are severely affected by their self-diagnosis due to a massive restriction of their food choice, quality of life, and social interaction, allergy societies in German-speaking countries have published a guideline which describes a pragmatic diagnostic and therapeutic approach. The primary aim is to alleviate symptoms by improving digestive function and to expand the choice of foods, rather than to exclude the suspected diagnosis. Collaboration with a dietician/nutritionist with allergological expertise is therefore strongly recommended.