Is onycholysis contagious?

Onycholysis is a gap between the nail plate and the skin beneath it. The lifted portion may look white, yellow, or opaque because air sits under the nail. Injury, repeated wet work, irritating products, skin conditions, and infection can all contribute. The separation does not pass from one person to another by ordinary contact. If fungus is the cause, the fungus may move through shared nail tools, towels, socks, or footwear, especially when moisture remains trapped.

Keep the nail short by carefully trimming only the unattached edge, and do not pull at the lifted section. Dry hands and feet thoroughly after washing, change damp socks, and avoid sharing clippers or files. Pause nail products while the cause is unclear. A clinician can examine the colour, texture, surrounding skin, and other nails; testing may be needed before treatment for fungus. See [Nail Fungus](/conditions/nail-fungus/) and [Nail Psoriasis](/conditions/nail-psoriasis/) for related causes.

Arrange an assessment if separation is spreading, affects several nails, keeps returning, or does not begin settling as the nail grows. Seek prompt care for increasing pain, warmth, swelling, pus, a foul smell, bleeding, or a dark colour that was not explained by an injury. People with diabetes, poor circulation, or reduced immunity should seek advice early when a nail is damaged or infected.

Could this be caused by fungus, psoriasis, an injury, or product irritation? Should the nail be tested before treatment? How should I trim and protect it while new nail grows?