Personal skincare leave-on products increase the risk of food allergies. Parents must be imparted with an elevated degree of cognizance regarding the allergenic nature of pediatric skincare products. Material and methodsWe aimed to examine the data inferred from the promotional material on labeling these products about their proclivity to elicit skin sensitization. This study investigated the relationship between food allergens and essential oil ingredients and highlighted marketing terms, product prices, and ratings of moisturizers for children that are sold on Amazon, Japan. We searched and recorded the product labels and website marketing terms, price (per gram or milliliter), the number of reviews, and allergens and investigated the relationship between the percentage of food allergens in those products and marketing terms, price, and the number of Amazon reviews. ResultsAmong the 164 pediatric skincare products we included, 144 (87.8%) that were manufactured in Japan were the most common; 7 (4.3%), 15 (9.1%), 23 (14.0%), 24 (14.6%), and 54 (32.9%) contained the eight regulated food allergens, grain, nut, fruit, and essential oils, respectively. Marketing terms emphasizing "natural/organic" were more likely to contain grain allergens and essential oils and were more expensive with and without "organic" labeling, respectively, whereas those labeled with marketing terms emphasizing "hypoallergenic" were less likely to contain fruit allergens or essential oils. Products with fewer Amazon reviews were more likely to use the marketing term "natural/organic" and had a higher grain allergen content. ConclusionIn Japan, 4.3% of children's skincare products sold on Amazon contain eight food allergens that should obligatorily be labeled when included in food products. In addition, more than 10% of these children's skin care products contain ingredients derived from nuts, while more than 30% contain fruit extracts or essential oils.