Inclusion criteria:  Patients evaluated at the Montpellier University Hospital, Allergy Unit ; Patients aged 5 years or older; Patients with a history of immediate reaction after consuming peanuts AND a positive peanut prick test; AND peanut positive specific serum IgE (ImmunoCAP®); AND a positive oral peanut challenge test OR a clinical history of anaphylaxis AND peanut-specific IgE> 100 kUA / L (ImmunoCAP®); Patients who started peanut OIT between September 2018 and January 2021.  Exclusion criteria:  Patients in exclusion period determined by a previous study; Patients under legal protection, under guardianship or under curatorship; Possible poor therapeutic compliance to the OIT protocol; Active malignant neoplasia or autoimmune disease; Active eosinophilic esophagitis or other gastrointestinal eosinophilic disorders; Severe active eczema; Pregnancy ; Cardiovascular disease and use of beta blockers and / or ACE inhibitors; Chronic urticaria; Mastocytosis.