Oral food challenge: to differentiate between a sensitization without clinical relevance and a food allergy, often a food challenge is performed. In addition, an oral food challenge should be performed to determine whether the child has outgrown his/her food allergy. This test will usually be conducted in our practice. The child will usually have to eat 5 doses of the food. After consulting the parents, we will choose a preparation which the child prefers to eat. Before and during the food challenge, the child is examined in detail, blood pressure and oxygen saturation are measured (if necessary also continuously during the test). For this test, we have a specific room with a qualified nurse, equipped with patient couches, also iPads and play area are available, as the whole challenge lasts approximately 4-5 hours. After the last dose, we allow an observation time of 2 hours, until the child is discharged from the office, because allergic reactions can sometimes occur only once certain foods are digested.