Most nose bleeds are harmless but they can still be alarming when they occur in an infant. The most likely cause of an infant nosebleed is dryness or irritation. Sometimes an infant can manage to scratch the inside of the nose with a fingernail, but picking isn't usually a problem during the first year of life.

Children most often experience nosebleeds as a result of picking the nose, according to KidsHealth.org, but this is less of a factor for adults.