The aim of this study is to gain more knowledge on the nutritional and immunological aspects of allergy to milk and eggs in children.

Food allergy in children is an emerging problem in many countries. Milk and eggs are important sources of nutrition in childhood. Restricting these products in children's diets can affect the quality of child's life and nutrition, which is paramount to good physical and mental child development during this vulnerable period of life. The aim of this study is to gain more knowledge on the nutritional and immunological aspects of immunoglobulin E (IgE) mediated allergy to milk and eggs in children. In this study we will analyze parent perceived child's quality of life, factual nutrition (assessed by 3-day food diaries), food allergy self efficacy measure for parents, parent perceived quality of life will be assessed using Food Allergy Quality of Life Questionnaire - Parent Form, anthropometric measures of children (height and weight), serum nutritional markers (vitamin D, calcium, magnesium, iron and phosphorous), sensitization tests (specific Immunoglobulin E (sIgE) to milk and egg and their components) as well as markers of allergic inflammation (interleukin 10, 13, 17, 25 and 33, eosinophil count and serum Immunoglobulin E). Food allergy will be confirmed by an oral food challenge (OFC), variables will be compared between different OFC outcomes (sensitized-allergic/sensitized-non-allergic).

Inclusion Criteria:

• Subjects from 6 months to 12 years of age and their parents / guardians.
• Subjects with suspected or confirmed allergy to chicken's egg and/or cow's milk. Suspected food allergy is defined as sensitization to a food that has not been consumed recently (in the last 3 months) without symptoms or sensitization to a food that has never been consumed. A confirmed food allergy is defined as a food allergy that has previously been confirmed by a positive result of an oral food challenge.
• Legal guardians of the subject are capable to sign a written informed consent form.

Exclusion Criteria:

• Subjects to whom food allergies are unlikely (who have recently eaten a suspected food without symptoms or who have not eaten food recently but have never had symptoms and are not sensitized).
• Subjects to whom an oral food challenge is contraindicated.
• Subjects with comorbid chronic diseases affecting the child 's nutrition and growth.
• Legal guardians of the subject do not wish to participate in the study or are unable to sign a written consent form.

Subjects from 6 months to 12 years of age with suspected or confirmed allergy to chicken's egg and/or cow's milk, referred for an oral food challenge with milk or egg will be enrolled.