Onycholysis
Pronunciation: on-ih-KOL-ih-sis
The painless separation of the nail plate from the underlying nail bed, beginning at the free edge and progressing proximally.
Full Definition
Onycholysis is a clinical sign characterised by the detachment of the nail plate from the nail bed, creating a white or yellowish discolouration as air fills the subungual space. It may be idiopathic or secondary to psoriasis, thyroid disorders, fungal infection, trauma, or phototoxic drug reactions. It differs from onychomycosis in that it is a structural finding rather than an infectious diagnosis, though the two may coexist. Editors must distinguish 'onycholysis' (nail separation) from 'onychomycosis' (fungal nail infection) and 'onychorrhexis' (longitudinal nail ridging), as these are frequently confused in manuscript drafts.
Usage
Usage note: Distinguish carefully from onychomycosis (fungal infection) and onychorrhexis (brittle, ridged nails). These three terms are a frequent source of error in dermatology manuscripts.
In Context
- "Nail psoriasis was documented in 34% of patients, with onycholysis and pitting being the most frequent findings." — Psoriasis outcomes study
- "The editor queried whether 'onycholysis' had been confused with 'onychomycosis' in the differential diagnosis section." — Copy-editing query