**Preface to "Nutrition, Diet and Food Allergy"**

Dietary modules and nutritional habits are fundamental to the growth of a child and ideal performance of the immune system during the first 1000 days of life. A modulation in both innate and adaptive immunity, shaping allergy development, is accomplished by the gut and skin microbiota. Interestingly, bacterial community structures have been found to be different among children affected by food allergies compared to healthy children.

Globally, food allergies affect 1.5% of adults and 5% of children, and this prevalence is increasing in recent decades, representing a public health problem. Different mechanisms are involved in food-allergic diseases with distinctive clinical characteristics: IgE-mediated and non-IgE-mediated phenotypes will be distinguished in the present Special Issue. In the first year of life, cow's milk allergy (CMA) represents the most common allergy. A focal point will be put on peculiar phenotypes of non-IgE mediated CMA, such as food-protein-induced enterocolitis syndrome and Heiner syndrome. Later in childhood, nut and fruit allergies taks hold, and this will be examined in this Special Issue by diagnostic work-up, as well as clinical features.

The management of these fascinating diseases will be discussed with particular attention on nutritional hazards, risks of allergic reactions to new allergens, and problems with mislabelling (precautionary allergen labelling (PAL)). Moreover, the dietary restrictions and the re-introduction of allergens lead to a significant burden for affected patients, fear of accidental ingestions, and related risk of severe reactions, resulting in a reduced quality of life among food-allergic patients. In particular, policies assumed in schools on food allergy will be inquired, focusing on management practices.

I really appreciated the opportunity of taking part of this remarkable work, and I am very thankful to all authors for their support.

> **Carla Mastrorilli** *Editor*
