2023 Volume 37 Issue 1 Pages 93-98
Objective: Few studies have been conducted on low dose oral food challenge (OFC) for severe peanut allergy in Japan. We aimed to determine an appropriate dose for the OFC for severe peanut allergy.
Methods: This retrospective study included patients who had allergic reactions to peanuts or had serum Ara h2-specific IgE levels of 4.0 UA/mL or higher and received a small dose (0.1 g or 0.3 g) of peanuts for OFCs at Showa University Hospital between January 2015 and December 2021. The OFCs were performed using an escalating 2-dose method involving an interval of 40 min.
Results: In total 51 cases were included, of which 33 were from the 0.1 g group and 18 were from the 0.3 g group. No significant differences were noted in background factors and allergen-specific IgE levels in both groups. The OFC-positive rate was significantly higher in the 0.3 g group (72.2%) than in the 0.1 g group (33.3%). A comparison of symptom grades by positive threshold dose showed that patients with a positive threshold of 0.03 g (1/3 amount of 0.1 g) had lower symptom grades than those with a threshold of 0.1 g (3/3 amount of 0.1 g and 1/3 amount of 0.3 g) or a threshold of 0.3 g (3/3 amount of 0.3 g).
Conclusion: The challenging dose for OFC for severe peanut allergies should be set to 0.1g or less.
