Onycholysis is distal separation of the nail plate from the nail bed, producing a white/opaque area that may accumulate secondary debris and pigment. It is a sign, not a diagnosis, with diverse causes including trauma/over-grooming, psoriasis, onychomycosis, contact irritants/allergens, photosensitizing drugs (tetracyclines), thyrotoxicosis, and Pseudomonas or Candida colonization. Management targets the underlying cause, eliminates trauma and moisture, and promotes re-adhesion as the nail grows out.
Etiologies
- Mechanical/traumatic: overzealous cleaning under nails, tight shoes, on-the-job microtrauma, long nails.
- Inflammatory: psoriasis (erythematous border, oil-drop patches), eczema, lichen planus.
- Infectious: onychomycosis (DLSO/WSO), Candida (especially thumbs in wet work), Pseudomonas (chloronychia—green discoloration).
- Chemical/phototoxic: acrylic nail adhesives, solvents, frequent polish removers; doxycycline/minocycline + UV exposure; psoralens.
- Systemic: hyperthyroidism (spooning, soft nails), pregnancy-associated changes, porphyria cutanea tarda.
- Idiopathic: especially in women with long nails.
Clinical Clues
- Psoriatic onycholysis: salmon patches, erythematous border at proximal onycholysis.
- Fungal: subungual debris, distal thickening; confirm with PAS/culture.
- Pseudomonas: green-black discoloration; often in wet exposure.
- Drug-induced: temporal relation to new meds and UV exposure.
Diagnosis
- History and exam with dermoscopy (erythematous rim in psoriasis; black/green pigment in Pseudomonas).
- Mycology (KOH/PAS/culture) if fungal cause suspected; bacterial culture if purulence or green discoloration.
- Consider TSH if systemic symptoms; patch testing for occupational/allergic triggers.
Management
- Universal measures
- Trim back detached nail; keep nails short; avoid cleaning under nail which worsens separation.
- Keep nail bed dry; cotton gloves under vinyl for wet work; avoid occlusion when possible.
- Discontinue exacerbating cosmetics (acrylics), solvents, and photosensitizing agents when feasible.
- Targeted therapy
- Psoriasis: topical high-potency corticosteroids under occlusion, vitamin D analogs; intralesional steroids for limited nails; consider systemic/biologics if severe nail/skin disease.
- Onychomycosis: treat per standards (terbinafine/itraconazole; or topical agents for mild involvement); debridement improves re-adhesion.
- Pseudomonas (chloronychia):
- Acetic acid or diluted bleach soaks (e.g., 1:4 white vinegar:water; or 0.05% sodium hypochlorite) 5–10 minutes daily.
- Topical fluoroquinolone drops/solutions; keep dry; rarely need oral ciprofloxacin.
- Candida: reduce wet exposure; topical azoles; treat paronychia if present.
- Contact/irritant: identify and eliminate allergens; topical steroids for inflamed folds; patch testing as needed.
- Drug-induced phototoxicity: stop or switch offending drug; strict photoprotection.
- Follow-up and Expectations
- Re-adhesion occurs with proximal nail growth; fingernails grow ~3 mm/month, toenails ~1 mm/month. Full normalization may take 4–6 months (fingers) or 12–18 months (toes).
- Persistent cavities predispose to secondary infections; maintain dryness and periodic debridement.
Prevention
- Short nails, protective gloves for wet work, gentle manicuring.
- Avoid chronic use of adhesives/acrylics without breaks; ensure salons follow infection control.
References (recent guidelines and reviews)
- Nail disorder diagnostics and management overviews, 2021–2024.
- Pseudomonas “green nail syndrome” case series and treatment strategies, 2021–2023.
- Psoriatic nail disease algorithms and outcomes, 2022–2024.