A safe and effective protocol for peanut oral immunotherapy

Oral Immunotherapy (OIT) to peanuts has been associated with an increased risk of anaphylaxis, with a risk ratio above 3 and need for epinephrine in about 25% of treated patients.[1] Main protocols start at a median dose of 0.5 mg of peanut proteins.[1] We are presenting preliminary data on a low-dose delayed dose increase OIT for peanuts, performed at the Allergy Unit of the University Hospital of Montpellier (France). We included 19 consecutive patients with a diagnosis of peanut allergy, reached through oral food challenge (OFC). We then decided to treat them with an OIT protocol, starting at the dose of 0.02 mg of peanut proteins. Doses were increased every 4 to 12 weeks, depending on the severity of the reported allergic reaction or of the results of the OFC (shorter delay in less severe patients). Patients had a median age of 12.7 years (min-max 5-31), 8 of them were females (42.1%). 6 of them had a clinical history of eczema (31.6%), 11 suffered from concomitant asthma (57.9%), 14 of them were atopic (73.7%), and 12 of them presented an allergy to another food (63.2%). 2 patients reported a clinical history of anaphylaxis (1 shock), 3 others had a clinical history of anaphylaxis and presented an anaphylactic reaction during the OFC (1 shock); 5 others presented an anaphylactic reaction during the OFC (1 shock. In total, 10 patients had a history or an OFC concluded because of anaphylaxis (52.6%) and 3 experienced an anaphylactic shock (15.8%). Patients underwent our local OIT protocol. Overall, they reached the average dose of 600 mg of peanut protein (median 400 mg). 10 patients (52.6%) tolerate now 400 mg of peanut, and 4 (21.1%) tolerate more than 1000 mg. No patient experienced any allergic reaction during the whole procedure, neither at the hospital, when doses were increased, nor at home, during maintenance phases. The present pilot study shows that peanut OIT starting at very low doses and with delayed doses increases, as proposed by our protocol, seems an effective and safe procedure even in patients having experienced peanut anaphylaxis.