Onycholysis

This code represents onycholysis, a condition characterized by the spontaneous separation of the nail plate from the nail bed, typically starting at the distal or lateral free edge and progressing proximally. The affected nail often appears discolored, opaque, and may accumulate debris under the separated portion.

Use this code when documentation clearly indicates the diagnosis of onycholysis, regardless of the underlying cause. This applies to cases where the nail plate has detached from the nail bed due to trauma, fungal infections, psoriasis, contact dermatitis, or systemic diseases. Supporting documentation should describe the nail separation and location.

• Do not use this code for complete nail avulsion or nail loss; those conditions have specific codes.
• Always look for an underlying cause (e.g., fungal infection, psoriasis) and code it as a primary or secondary diagnosis if documented.
• Ensure the documentation specifies which nail(s) are affected if relevant for clinical context, though this code is not laterality-specific.