What are the treatment options for toenail discoloration?

Treatment Options for Toenail Discoloration

Toenail discoloration is most commonly caused by onychomycosis (fungal infection), which requires specific treatment based on the type and severity of infection. For most cases of toenail discoloration due to onychomycosis, oral terbinafine is the preferred treatment due to its superior effectiveness and shorter treatment duration compared to topical therapies. 1

Diagnosis Before Treatment

Before initiating treatment, proper diagnosis is essential:

• Laboratory confirmation through potassium hydroxide preparation with fungal culture, periodic acid-Schiff stain, or polymerase chain reaction is recommended to confirm fungal infection 1
• Nail specimens should be taken from discolored, dystrophic, or brittle parts of the nail 2
• Non-fungal causes of nail discoloration must be ruled out, including:
  • Bacterial infection (particularly Pseudomonas which causes green discoloration) 3
  • Psoriasis, trauma, lichen planus, and yellow nail syndrome 2

Treatment Options Based on Clinical Pattern

1. Oral Antifungal Therapy

• First-line treatment for moderate to severe onychomycosis:

  • Terbinafine: Most effective oral agent, especially for dermatophyte infections 1, 4
  • Itraconazole: Alternative option when terbinafine is contraindicated 4
  • Fluconazole: Used off-label in some cases 4

• Caution: Monitor for drug-drug interactions when using terbinafine with:

  • Tricyclic antidepressants, SSRIs, atypical antipsychotics, beta blockers, or tamoxifen 1

2. Topical Antifungal Therapy

• Appropriate for mild to moderate cases, especially when limited to distal nail plate:

  • Ciclopirox 8% nail lacquer: Applied daily as part of a comprehensive management program 5
  • Efinaconazole 10% solution 1
  • Tavaborole 5% solution 1

• Application instructions for ciclopirox 8% nail lacquer:

  • Apply evenly over the entire nail plate and 5mm of surrounding skin 5
  • If possible, apply to nail bed, hyponychium, and under surface of detached nail plate 5
  • Requires professional removal of unattached, infected nail as frequently as monthly 5
  • Treatment duration up to 48 weeks may be necessary 5

3. Adjunctive Treatments

• Nail debridement and trimming:

  • Removal of unattached, infected nail improves penetration of topical medications 5
  • Should be performed by healthcare professionals with expertise in nail disorders 5

• For bacterial causes (Green Nail Syndrome):

  • Cutting the detached nail plate 6
  • Topical antibiotics such as tobramycin eye drops 3
  • Brushing with 2% sodium hypochlorite solution twice daily 6

Treatment Selection Based on Clinical Pattern

1. Distal and Lateral Subungual Onychomycosis (DLSO):

   • Most common pattern affecting toenails 2
   • Characterized by thickened, discolored nails with onycholysis 2
   • Treatment: Oral terbinafine for extensive cases; topical therapy for mild cases 1

2. Superficial White Onychomycosis (SWO):

   • Presents as crumbling white lesions on nail surface 2
   • Common in children, usually caused by T. interdigitale 2
   • Treatment: May respond to topical therapy if superficial; deep forms require oral therapy 2

3. Proximal Subungual Onychomycosis (PSO):

   • Uncommon pattern except in immunocompromised patients 2
   • May be a marker for HIV infection 2
   • Treatment: Oral antifungals recommended due to deeper infection 4

4. Total Dystrophic Onychomycosis (TDO):

   • Advanced stage where nail plate is almost completely destroyed 2
   • Treatment: Typically requires oral antifungal therapy 4

5. Candidal Onychomycosis:

   • Often associated with chronic paronychia 2
   • Treatment: Address underlying factors (water exposure) plus antifungal therapy 2

Prevention of Recurrence

• Avoid walking barefoot in public places 1
• Disinfect shoes and socks regularly 1
• Professional podiatry care for high-risk patients (e.g., diabetics) 7

Important Considerations

• Complete cure rates are relatively low (less than 12% in clinical studies) 5
• Treatment duration is lengthy (6-12 months) 2
• Relapse rate is approximately 25% even with successful treatment 1
• Untreated onychomycosis can cause pain, discomfort, and physical impairment 1
• In diabetic patients, onychomycosis can lead to serious complications including foot ulcers 2