Onycholysis
Pronunciation: on-ih-KOL-ih-sis
The painless separation of the nail plate from the nail bed, beginning distally or laterally, seen in psoriasis, fungal infection, and thyroid disease.
Full Definition
Onycholysis is the distal or lateral detachment of the nail plate from the underlying nail bed, creating a white or yellowish opacity as air replaces the normal translucent attachment. It is a non-specific nail sign encountered in psoriatic nail disease, onychomycosis, trauma, hyperthyroidism, and phototoxic drug reactions. Editors should distinguish it from onychomadesis (proximal nail shedding) and subungual hyperkeratosis. The term is a single word and should not be hyphenated. It appears in rheumatology, endocrinology, and dermatology correspondence and must be spelled with the 'y' ('onych-'), reflecting its Greek root for nail.
Usage
Usage note: Do not confuse with onychomycosis (fungal nail infection), which is a cause rather than a synonym of onycholysis.
In Context
- "Onycholysis affecting the third and fourth fingernails was noted, consistent with psoriatic nail disease." — Rheumatology-dermatology joint clinic letter
- "The nail assessment documented onycholysis of three toenails and referred the patient for mycology swabs." — Podiatry referral letter