onycholysis

Onycholysis is the separation of the nail plate from the nail bed, typically beginning at the distal edge and progressing proximally. The exposed portion of the nail bed often appears pink or yellow and may look opaque, with the detached nail lifting away from the skin. The condition can be painless or become painful if there is secondary infection or significant lifting.

The condition has a variety of causes. Trauma from repeated finger or toe injuries, manicures, or aggressive nail care is a common trigger. Fungal infections (onychomycosis) can cause or accompany onycholysis. Irritant or allergic contact dermatitis to nail polishes, acetone, acrylates, or other nail products is another frequent cause. Dermatoses such as psoriasis or eczema, inflammatory skin conditions, and lichen planus can be associated with onycholysis. Systemic diseases, including thyroid disorders, may be linked. Certain medications or chemical exposures can also contribute.

Diagnosis is usually clinical, based on the appearance of the detached nail. Testing may be used to rule out fungal infection, including microscopy with potassium hydroxide (KOH) preparation, fungal culture, or PCR. In uncertain cases or when the diagnosis is unclear, referral to a dermatologist may be appropriate.

Management focuses on addressing the underlying cause. This includes protecting the nails and avoiding further trauma, minimizing moisture and irritants, and treating any skin disease. If a fungal infection is present, appropriate antifungal therapy—topical or oral—as advised by a clinician is used. Stopping or changing a triggering cosmetic product or medication is important. Secondary bacterial infections require appropriate antibiotic treatment. Nail growth is gradual, and new nail regrowth occurs as the bed heals, often taking months to complete.