That is prefectly normal everybody gets him no worries
that can be dead skin or it can be an immune deficiency infection so to be on the safe side I would go to the doctor if it is an immune deficiency the Dr. will give you an antiobidic & you'll be fine. It is nothing at all to worry about.
Dr. Oz just covered this. See if this is the right one:
http://www.doctoroz.com/videos/what-your-nails-are-telling-about-your-health