What is the best course of treatment for a 54-year-old male patient with onychomycosis, subungual hematomas, and a history of a bloody blister on the toes, currently being treated with CeraVe (moisturizer) cream, Epsom salt foot baths, and terbinafine (antifungal medication)?

Treatment of Onychomycosis in a 54-Year-Old Male Patient

Terbinafine 250 mg daily for 12 weeks is the optimal treatment for this patient's toenail onychomycosis, as it has superior efficacy compared to other antifungal medications with cure rates of 70-80% for toenail infections. 1

Evaluation of Current Treatment Plan

The current treatment plan includes:

• Daily terbinafine for three months
• Epsom salt foot baths for 10 minutes nightly
• CeraVe cream for moisturizing

Appropriateness of Systemic Therapy

The presence of multiple affected toenails with onychomycosis warrants systemic therapy. The British Association of Dermatologists guidelines strongly support this approach:

1. Terbinafine is the first-line treatment for dermatophyte onychomycosis based on:

   • Higher efficacy compared to itraconazole (55% vs 26% complete cure at 72 weeks) 1
   • Lower relapse rates (23% vs 53% for itraconazole) in long-term follow-up 1
   • Fungicidal (rather than fungistatic) activity against dermatophytes 1

2. Dosing regimen:

   • 250 mg daily for 12-16 weeks for toenail infections 1
   • Continuous daily dosing is superior to pulse dosing 2

Management of Subungual Hematomas

The patient also has subungual hematomas on the right and left 3rd toenails. These should be addressed separately from the onychomycosis:

• Monitor for resolution as these typically resolve on their own as the nail grows out
• If painful or causing significant discomfort, consider nail trephination to relieve pressure
• Ensure proper footwear to prevent further trauma

Comprehensive Treatment Algorithm

1. Confirm diagnosis (ideally should be done before starting treatment)

   • Microscopy and culture should be performed before initiating therapy 1
   • This is particularly important as treatment failure may occur if the causative organism is not a dermatophyte

2. Systemic therapy

   • Continue terbinafine 250 mg daily for 12 weeks as prescribed
   • Monitor for potential side effects:
     • Gastrointestinal symptoms (49% of cases): nausea, diarrhea, taste disturbance 1, 3
     • Dermatological reactions (23% of cases): rash, pruritus, urticaria 1
     • Rare but serious: hepatotoxicity, Stevens-Johnson syndrome 1, 3

3. Adjunctive measures

   • Continue Epsom salt foot baths as they help soften the nail and may improve penetration of topical agents
   • Continue CeraVe cream for skin hydration, which has already helped resolve the bloody blister
   • Consider mechanical debridement of affected nails if they are thickened, as this may improve treatment outcomes

4. Monitoring

   • Re-evaluate after 3-6 months from treatment initiation 1
   • Further treatment should be given if the disease persists
   • Complete nail regrowth may take 12-18 months even after successful treatment

Important Considerations and Potential Pitfalls

1. Baseline laboratory testing

   • Consider baseline liver function tests and complete blood count, especially if the patient has:
     • History of heavy alcohol consumption
     • Pre-existing liver disease
     • History of hepatitis 1, 3

2. Drug interactions

   • Terbinafine has minimal drug-drug interactions compared to azoles 1, 4
   • Main interaction is with drugs metabolized by cytochrome P450 2D6 isoenzyme 1

3. Treatment failure considerations

   • If treatment fails, consider:
     • Poor compliance
     • Poor absorption
     • Immunosuppression
     • Dermatophyte resistance
     • Subungual dermatophytoma preventing drug penetration 1
   • In cases of treatment failure, either an alternative drug or partial nail removal in combination with further therapy may be necessary 1

4. Patient education

   • Warn about potential taste disturbance, which can be permanent in rare cases 1, 3
   • Advise to report any symptoms of liver problems immediately (nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice) 3
   • Minimize sun exposure as terbinafine can cause photosensitivity 3

The combination of systemic terbinafine with appropriate foot care (Epsom salt soaks and moisturizing) represents an evidence-based approach to treating this patient's onychomycosis while addressing the resolved bloody blister and monitoring the subungual hematomas.