What is the treatment for oncholysis of the toenail?

Treatment of Toenail Onycholysis

The treatment of toenail onycholysis depends critically on the underlying cause: if fungal infection (onychomycosis) is confirmed, oral terbinafine is the definitive treatment; if non-fungal (traumatic, drug-induced, or idiopathic), management focuses on promoting nail reattachment through protective measures, keeping the area dry, and removing the separated nail plate when necessary. 1

Initial Diagnostic Step

Before initiating any treatment, you must distinguish between fungal and non-fungal onycholysis:

• Obtain nail specimens for laboratory confirmation (KOH preparation, fungal culture, or nail biopsy) to diagnose onychomycosis before starting antifungal therapy 2
• Non-fungal onycholysis in toenails is typically mechanical, resulting from pressure on toes from closed shoes during walking, especially with flat feet producing asymmetric gait 3

Treatment Algorithm by Etiology

For Fungal Onycholysis (Onychomycosis)

Oral terbinafine 250 mg once daily for 12 weeks is the treatment of choice for toenail onychomycosis 2:

• Achieves mycological cure in 70% of patients at 48 weeks (12 weeks treatment plus 36 weeks follow-up) 2
• Effective treatment (mycological cure plus minimal nail involvement) occurs in 59% of patients 2
• Mean time to overall success is approximately 10 months due to slow nail regrowth 2
• Clinical relapse rate is approximately 15% at one year post-treatment 2

Critical monitoring requirements:

• Patients must immediately report persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine, or pale stools (hepatotoxicity warning) 2
• Report taste/smell disturbances or depressive symptoms 2
• Discontinue immediately if hives, mouth sores, blistering/peeling skin, or difficulty swallowing occur 2

For Non-Fungal Onycholysis

The primary goal is promoting nail reattachment as quickly as possible to prevent irreversible nail bed keratinization 1:

Grade 1 (Mild) - Asymptomatic or Minimal Symptoms

• Continue monitoring while maintaining current activities 1
• No treatment interruption required if drug-induced 1
• Apply daily topical emollients to periungual folds, matrix, and nail plate 1
• Use protective nail lacquers to limit water loss 1

Grade 2 (Moderate) - Painful or Functionally Limiting

• Partial or total nail avulsion is required for painful hematoma or subungual abscess 1
• Clean and culture the nail bed during removal 4
• Treat any identified infection with appropriate topical/oral antibiotics and antiseptics 4
• Cut nails regularly until the plate grows reattached 4

Grade ≥3 or Intolerable Grade 2

• Interrupt causative treatment immediately until severity decreases to Grade 0-1 1
• Remove nail plate in severe and/or painful lesions 4

Essential Protective Measures for All Non-Fungal Cases

Drying strategy (most important for fingernails but applicable to toenails):

• Dry the onycholytic area with a hair dryer, as all colonizing organisms are moisture-loving and perish in dry environments 3
• This addresses secondary colonization by Candida or Pseudomonas without requiring antifungal treatment 3

Daily preventive care:

• Apply topical emollients on periungual folds, matrix, and nail plate 1, 4
• Use protective nail lacquers 1, 4
• Wear cotton socks and comfortable, well-fitting shoes 4

Activities to avoid:

• Manipulation of cuticles and nail biting 1, 4
• Using toenails as tools 1, 4
• Prolonged soaking in water 1, 4
• Exposure to solvents or harsh chemicals 1, 4
• Application of artificial nails 1, 4

Special Considerations for Drug-Induced Onycholysis

For taxane-related onycholysis (chemotherapy patients):

• Frozen socks should be systematically used during chemotherapy infusions, reducing toenail changes from 21% to 0% 1, 4
• Use frozen socks at -10 to -30°C for total duration of 90 minutes 4

For photo-onycholysis (drug + UV exposure):

• Discontinue the offending medication (commonly NSAIDs, tetracyclines, fluoroquinolones) 5
• Condition typically resolves within 3 months without sequelae 5

Critical Pitfalls to Avoid

• Failing to remove the nail when indicated leads to chronic onycholysis and persistent subungual hyperkeratosis 1
• Treating presumed fungal infection without laboratory confirmation wastes time and exposes patients to unnecessary medication risks 2
• Inadequate cleaning and debridement of the nail bed during removal causes complications 1
• Mistaking secondary Candida colonization for the primary cause in non-fungal onycholysis leads to ineffective antifungal treatment 3