Without seeing it, I can't be sure. It is possibly genetic. It could be due to an injury as well. You might see if any other family members have this. If you are concerned or it hurts him, you might see a podiatrist or dermatologist.
Posted By Vivian Abrams DPM on April 18, 2006 at 23:26:51:
In Reply to: 4th toenail
posted by Carrie F on April 18, 2006 at 16:16:52:
A layer of gel combined with a foot cover to help protect metatarsals and toes from friction and pressure. It also ideal for cushioning the ball of foot and provides warmth for people suffering from arthritis or poor circulation to the toes.