Dr Phil Kieran: How can I stop my son from biting his nails?

"Nailbiting, or onychophagia, can lead to sore fingertips, which are more prone to infection if the nail is bitten very short. It can also lead to dental issues such as chipped enamel, gum injuries or gingival infection due to minor trauma."

Pic: iStock

My four-year-old has started to bite his nails - often when watching TV. Is there an over-the-counter treatment you'd recommend?

Nail biting in children is common, with approximately 20-30% developing the habit. Most of the time, the nail-biting is mild, and the child will grow out of it before 12.