Low-dose oral food challenges.

Background: Infants aged <1 year with confirmed food allergies generally need to avoid causative foods completely for a certain period. Low-dose oral food challenges (LD-OFCs) may be an effective strategy for safely introducing small amounts of causative foods to individuals with food allergies. This study clarified the safety of LD-OFCs in infants aged <1 year with food allergies.

Methods: We retrospectively analyzed the clinical records of LD-OFCs performed in infants aged <1 year allergic to hen's egg, cow's milk, or wheat between April 2014 and October 2017. Approximately 1/25th-1/20th of the egg white from a heated whole hen's egg, 3 mL heated cow's milk, and 2 g wheat noodles (udon) were used as challenge foods. We examined the LD-OFC results, including the induced symptoms and treatment required for positive LD-OFC results.

Results: The LD-Egg, LD-Milk, and LD-Wheat OFC groups comprised 68, 42, and 13 participants, respectively. The positivity rates for the LD-Egg, LD-Milk, and LD-Wheat OFC groups were 7%, 24%, and 0%, respectively. Patients predominantly exhibited skin symptoms, and most were treated with oral antihistamines alone. None of the patients experienced anaphylaxis or required adrenaline injections.

Conclusions: Infants aged <1 year with food allergies can safely undergo LD-OFCs by consuming low doses of causative foods. Avoiding the complete elimination of causative foods is an important strategy for managing infants with food allergies when initially introducing causative foods.