Onychoschizia is a nail condition that shows as peeling or splitting of the nail plate into thin layers at the free edge, usually caused by repeated wet and dry cycles, detergents and solvents.
Also known as: peeling nails, splitting nails, lamellar dystrophy, flaking nails
Onychoschizia is the medical name for peeling nails. The nail plate is built from layers of keratinised cells. When the layers separate at the free edge, the tip flakes in thin sheets. DermNet describes it as distal lamellar splitting, or brittle nails, caused by water and detergent damage (DermNet).
The main cause is repeated wetting and drying. The plate swells in water and shrinks as it dries, and each cycle loosens the bond between layers. Frequent hand washing, dishwashing without gloves, swimming and long baths all count. Solvents add to it. Acetone and other removers dehydrate the plate, and long soaks for gel removal do most harm (Sinclair Dermatology). Peeling gel or acrylic off the nail takes the top layers of plate with it.
Care is about keeping water and solvents out and moisture in. Gloves for wet work, short soaks, and a nail or cuticle oil every day keep the plate flexible so it bends under pressure. Filing the free edge in one direction, with a fine file, avoids new splits. Nail hardeners with formaldehyde can make the problem worse, because over-crosslinked keratin becomes brittle (Salon Geek).
Peeling usually improves within a few months of the change, because the damaged plate grows out and new plate replaces it. Peeling that affects all nails, comes with pitting, colour change or lifting from the nail bed, or does not improve with care, is a reason to see a GP or dermatologist (Mayo Clinic).