Talk to your doctor if you regularly bite your fingers and nails. The most significant physical complication of dermatophagia is infection.
Dermatophagia is a compulsion disorder of gnawing or biting one's own skin, most commonly at the fingers. This action can either be conscious or unconscious. Those affected with dermatophagia typically bite the skin around the nails, There is not yet a known way to remedy this in adults. Small things can be done to.
My fingers, raw and red and sometimes bleeding, are justifiably the cause a disorder that has made me chew on my fingers for over 20 years.
I have no idea when I graduated from chewing on pencils to chewing on my fingers—maybe I always did both. Kids don't think about such.