When I cut his toenails (he's 5) there are usually small black hairs under the nail, not growing or attached but just there. They are about 5mm long and thick. He has darkish blonde hair so they aren't even the right colour! They are vertical 'down' the nail rather than across so its not something that he has picked up with bare feet and when I pull them out the nail bed isn't inflamed like you would expect if a foreign body got in there, but they are not attached to anything either. I can only assume its a weird keratin thing
Anyone else ever seen this?