Starts at the ends of the nails and raises the nail up: This ised "distal subungual onychomycosis." It is the most common type of fungal infection of the nails in boths and children. It is more common in the toes than the fingers, and the great toe is usually the first one to be affected.. - Don 't be embarr.ed if you have toenail or fingernail fungus. It 's way more common than you think. Fungi are tiny organisms you can only see . - Visible signs of a fungal nail infection include: scaling under the nail, which ised subungual hyperkeratosis. white or yellow streaks on the nail, which ised lateral onychomycosis. a crumbling corner or tip of the nail, which ised distal onychomycosis..Jump to Identifying Nail Fungus - Learn the causes. Nail fungus is most often caused by a dermatophyte fungus, but the infection can also stem from .