Noses humidify and warm the air that we breathe via a network of tiny blood vessels just inside the nostrils. This area is very delicate, and it also sees a lot of action—infections, dry air, as well as tiny fingers searching for boogers. As a result, around 30 percent of children under age 5 and 50 percent of kids ages 6 to 10 will have at least one nosebleed.
If your child has repeated nosebleeds, weather and nose picking are most likely to blame, though colds, allergies, and staph infections can also be factors. Pediatricians often recommend putting petrolatum or antibiotic ointment inside the nostrils and using a humidifier (hot or cool) in a child’s bedroom to help the nose heal.
During a nosebleed, you should apply steady pressure to your child’s nostrils (not the bridge of the nose) for five to ten minutes in order to get the bleeding to stop. Very frequent nosebleeds may indicate any number of chronic or serious conditions ranging from a foreign body in the nose to a bleeding disorder. Your pediatrician will take a thorough medical history and look in your child’s nose to get a better idea of what might be happening. Nosebleeds are rare under age 2, so if your baby or toddler develops one, be sure to tell his doctor.
Source: https://www.parents.com/