What is the treatment for Trichophyton rubrum (T. rubrum) onychomycosis in a patient with Crohn's disease (CD)?

From the Guidelines

The treatment for Trichophyton rubrum onychomycosis in patients with Crohn's disease should be oral terbinafine (250 mg daily for 6-12 weeks for fingernails or 12-16 weeks for toenails) due to its efficacy against T. rubrum and favorable safety profile, as recommended by the British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1.

Key Considerations

• The choice of therapy should balance effective eradication of the fungal infection while minimizing exacerbation of Crohn's disease symptoms.
• Before starting treatment, liver function tests should be performed and monitored during therapy, especially important for Crohn's patients who may already have altered liver function or be on hepatotoxic medications 1.
• Drug interactions between antifungals and Crohn's medications like biologics, immunomodulators, or corticosteroids must be carefully evaluated.

Alternative Options

• For patients with Crohn's disease who cannot tolerate oral antifungals due to gastrointestinal concerns or immunosuppressive therapy interactions, topical options like ciclopirox 8% nail lacquer applied daily for up to 48 weeks may be used, though with lower success rates 1.
• Itraconazole pulse therapy (200 mg twice daily for 1 week per month, repeated for 2-3 months for fingernails or 3-4 months for toenails) is an alternative that may reduce drug interaction risks, but its use should be carefully considered due to potential hepatotoxicity and interactions with other medications 1.

Severe Cases

• In severe cases or for patients with multiple contraindications, nail removal followed by topical treatment may be necessary.

Evidence Summary

The British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1 provide a comprehensive overview of treatment options for onychomycosis, including oral and topical antifungals. The guidelines recommend terbinafine as the first-line treatment for dermatophyte onychomycosis due to its efficacy and favorable safety profile. Subsequent studies have reported similar cure rates with a lower risk of drug interactions, supporting the use of terbinafine as the first-line treatment 1.

From the FDA Drug Label

The effectiveness and safety of Ciclopirox Topical Solution, 8%, (Nail Lacquer), in the following populations has not been studied The clinical trials with use of Ciclopirox Topical Solution, 8%, (Nail Lacquer), excluded patients who: were pregnant or nursing, planned to become pregnant, had a history of immunosuppression (e.g., extensive, persistent, or unusual distribution of dermatomycoses, extensive seborrheic dermatitis, recent or recurring herpes zoster, or persistent herpes simplex), were HIV seropositive, received organ transplant, required medication to control epilepsy, were insulin dependent diabetics or had diabetic neuropathy. Ciclopirox Topical Solution, 8%, (Nail Lacquer), as a component of a comprehensive management program, is indicated as topical treatment in immunocompetent patients with mild to moderate onychomycosis of fingernails and toenails without lunula involvement, due to Trichophyton rubrum

The treatment for Trichophyton rubrum (T. rubrum) onychomycosis in a patient with Crohn's disease (CD) is not directly addressed in the provided drug labels. However, based on the information provided, Ciclopirox Topical Solution, 8%, (Nail Lacquer), is indicated for the treatment of mild to moderate onychomycosis due to T. rubrum in immunocompetent patients.

• Since patients with Crohn's disease may be considered immunocompromised due to their condition or medications used to treat it, the safety and efficacy of Ciclopirox Topical Solution, 8%, (Nail Lacquer) in this population has not been established.
• Therefore, the use of Ciclopirox Topical Solution, 8%, (Nail Lacquer) in patients with Crohn's disease should be approached with caution and under medical supervision 2, 2, 2.
• Key considerations for treatment include:
  • The patient's immune status
  • Potential interactions with other medications
  • The severity of the onychomycosis
  • The presence of other underlying medical conditions.

From the Research

Treatment Options for Trichophyton rubrum (T. rubrum) Onychomycosis

• The treatment for T. rubrum onychomycosis typically involves oral antifungal medications, such as terbinafine, itraconazole, and fluconazole 3.
• Terbinafine has been shown to be effective in treating T. rubrum onychomycosis, with a study demonstrating that 250 mg of oral terbinafine per day for 6 months resulted in all 11 patients being clinically and mycologically normal 4.
• Intermittent pulse-dosed terbinafine has also been shown to be effective, with a study demonstrating that 93% of patients were cured with no evidence of decrease in efficacy when treated with 250 mg of terbinafine for 7 consecutive days every 3 months 5.
• Itraconazole is also a viable option, particularly in cases where terbinafine resistance is suspected 6, 7.

Considerations for Patients with Crohn's Disease (CD)

• When treating a patient with CD, it is essential to consider the potential interactions between the antifungal medication and the patient's underlying condition.
• There is no specific evidence to suggest that the treatment for T. rubrum onychomycosis would differ in patients with CD, but it is crucial to monitor the patient's response to treatment and adjust the therapy as needed 6, 3.

Antifungal Susceptibility

• The susceptibility of T. rubrum to antifungal agents is an essential consideration in treatment, with terbinafine and itraconazole showing high activity against the fungus 7.
• Fluconazole has been shown to have reduced susceptibility against T. rubrum, and griseofulvin's effectiveness can vary among strains 7.