The goal of this observational study is to learn about repetitive anaphylactic reactions in food allergic patients and to compare the frequency of repetitive reactions between different elicitors in food allergic patients. The main question it aims to answer are:

• Is there an elicitor specific difference in the occurrence of anaphylactic reactions once the elicitor has been identified and the patient received counselling about its avoidance?

Participants will answer questionnaires via a link they will receive via e-mail at baseline and 3, 6, 12 and 24 months after inclusion in the study.

The aim of the study is to establish a cohort of patients who were included in the anaphylaxis registry with an anaphylactic reaction to legumes, tree nuts, seeds, grains or pseudocereals within the previous twelve months. Patients are requested to provide information about the occurrence of new allergic reactions at defined time-points over a period of two years (at baseline, 3, 6, 12, and 24 months). In addition, their eating behavior and the food allergy-specific quality of life will be captured. The investigators intend to track self-management in dealing with anaphylaxis, especially the use of emergency medication. It is examined whether patients react again and whether these are reactions to a known or previously unknown allergen to the patient. By recording the symptoms, it will be checked whether there are certain reaction patterns to specific foods or whether these are patient specific. In addition, the influence of the previous anaphylactic reaction and knowledge of the existing allergy on quality of life, dietary behavior and the ability to use emergency medication should be examined.

This is intended to help improve the care for future patients in order to minimize the risk of repeat reactions.

Inclusion Criteria:

• anaphylactic reaction to peanuts, other legumes, tree nuts, seeds (e.g. sesame seed, sunflower seed), cereals (e.g. wheat, oat) or pseudocereals (e.g. quinoa)
• participation in the European Anaphylaxis Registry (Clinical Trials Identifier: NCT05210543)
• possibility and consent to receive links to the follow-up electronic surveys via e-mail and fill out the questionnaires electronically

Exclusion Criteria:

• if inclusion criteria are fulfilled there are no further exclusion criteria

The study population consists of patients (age 18 years or older) or their parents (patients age 0-17 years). Eligible patients have suffered at least one anaphylactic reaction to peanuts, other legumes, tree nuts, seeds (e.g. sesame seed, sunflower seed), cereals (e.g. wheat, oat) or pseudocereals (e.g. quinoa) within 12 months prior to presentation in a specialised food allergy center that is participating in the European Anaphylaxis Registry and in addition the EPAP follow-up project. If the patient or their parents agree to participate in the European Anaphylaxis Registry and fulfill the other inclusion criteria, they can also participate in the follow up study. We aim to include 322 patients.