The safety and health of our consumers are our top priorities, especially when having your little ones in mind, and it's disheartening to hear this happened. While all our whitening toothpaste undergoes extensive tests and is labeled to be safe and effective for any user over 12, some people may not tolerate a particular formulation, as flavor oils and other abrasives all have some potential to irritate. Usually, not brushing too hard or using a soft-bristled toothbrush minimizes these effects, and these temporary irritations do subside. If it persists or becomes uncomfortable, please discontinue use and consult your dentist. We take feedback like this very seriously, and our team would love to look into this further to see how this situation can be improved. Please call us at 1-800-492-7378, M-F, 9 am to 6 pm EST, so we can review the details of your report.