There has been a paradigm shift from allergenic food avoidance to consumption in early infancy in the prevention of food allergy. This is because it has been revealed that the cause of food allergy is not intestinal sensitization but mainly percutaneous sensitization, and oral consumption has been found to result in immune tolerance. Indeed, it was the first randomized controlled trial in 2015 that clarified that early consumption in infancy prevents the development of food allergy. To date, six randomized controlled trials have been reported on preventing egg allergy. A meta-analysis of these six studies revealed that the onset of egg allergy is prevented by the early consumption of egg. However, it is necessary to pay attention to the possibility of inducing an immediate allergic reaction in actually practicing this preventive method. For this reason, position papers on preventing egg allergy in several countries recommend that “heated egg” be introduced “from a small amount” in order to reduce the risk of adverse events. The timing of starting ingestion etc. is stratified by atopic dermatitis. However, little guidance is provided on how to increase quantities eaten afterwards. Future studies must provide information regarding the rate of increase, frequency, and duration of ingestion.