Can I check why do my baby 7 months old plu get ulcer? and what can I apply?

i read that ulcers, or gingivostomatitis, are caused by the HSV-1 virus, which most people pick up in their early childhood and carry for the rest of their lives. It can also be caused by a coxsackie virus, the culprit in hand, foot and mouth disease. Ulcers can also happen due to stress, injury (when your baby bites the insides of the cheek) and also from vitamin B, iron or zinc deficiencies. Bonjela is a great for ulcers but if you are looking for something natural, you can use honey as it has anti-microbial properties which helps ulcers heal faster. BUT if your child is under 1 year old, please do not use this method as it can cause baby to fall really sick. Coconut water works too.