Onychoschisis

Onychoschisis (or schizonychia) is a splitting of the nail plate. This is a rare nail disease in which the nail plate splits into two or more parts, starting from the free edge of the nail to the cuticle.

The causes of onychoschisis are not completely clear. It is assumed that this can be caused by nail trauma, congenital abnormalities of the nail plate, keratinization disorders, and vitamin and mineral deficiencies. Also risk factors are psoriasis, eczema, and fungal nail infections.

Clinical manifestations include the appearance of a longitudinal fissure in the nail, which deepens towards the base as the nail grows. The gap can cover the entire nail plate or only part of it. It has smooth edges, usually without signs of inflammation. Peeling a nail can be painful.

Diagnosis is based on visual examination and exclusion of other nail diseases. Treatment consists of eliminating the cause, using vitamins and strengthening agents. In severe cases, surgery may be required. The prognosis depends on the severity and cause of onychoschisis. With timely treatment, the nail can be restored.

**Onychoschisis or onycholysis?**

“It’s still a dilemma. How important is it for me to understand? Where is the answer that will reconcile me?”

This problem is extremely rare, which creates difficulties in differential diagnosis. The fundamental difference is that onycholysis is called leukonychia, that is, damage to the nail plate on the hands and feet (differentiation from the dystrophic process is needed); and with onychoschisis there is damage to the matrix and subungual zone. Diagnosed by examination under an electron microscope. This disease affects both women and men, and is associated with chronic eczema of the nails and hands. The peak incidence occurs after 50 years of age. There are two types: palmoplantar and true. Both forms will be presented in the description.

The causes of onychoschipsis are varied and unknown. The influence of heredity is assumed. An atypical type of onycholithiasis is considered a severe disorder, the characteristic manifestations of which are specific itching, thickening of the nails and tissue destruction. There is a possibility of communication