Onychoschizia is a splitting of the distal nail plate into layers at the free edge, a very common problem among women and represents a dyshesion of the layers of keratin, possibly as a result of dehydration. It usually occurs in children under 16. It also occurs in hooved animals such as horses and responds favorably to treatment with vitamin B7, also known as biotin.
- James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. p. 786. ISBN 0-7216-2921-0.
- Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 978-1-4160-2999-1.[page needed]
- Colombo, Victor E.; Gerber, Françoise; Bronhofer, Max; Floersheim, George L. (December 1990). "Treatment of brittle fingernails and onychoschizia with biotin: Scanning electron microscopy". Journal of the American Academy of Dermatology. 23 (6): 1127–1132. doi:10.1016/0190-9622(90)70345-i. PMID 2273113.