Report of a Case of a Dermatophytoma Successfully Treated With Topical Efinaconazole 10% Solution

May 2015 | Volume 14 | Issue 5 | Case Reports | 524 | Copyright © May 2015


Wendy Cantrell DNP, Theresa Canavan MD, and Boni Elewski MD

University of Alabama, at Birmingham, Department of Dermatology, Birmingham, AL

Abstract
Onychomycosis is a common fungal infection of the nail unit that results in discoloration, subungual debris, thickening, onycholysis, and often pain and impairment of mobility. Dermatophytomas are characterized by a thick fungal mass within and under the nail plate and are especially resistant to treatment. Here we report a case of a patient with a dermatophytoma who had failed oral terbinafine but was successfully treated with efinaconazole 10% topical solution.

J Drugs Dermatol. 2015;14(5):524-526.

INTRODUCTION

Onychomycosis accounts for roughly 1/3 of all skin fungal infections, and although onychomycosis is common it is also often difficult to treat and can have significant deleterious effects on patient’s quality of life.1 Distal and lateral subungual onychomycosis (DLSO), which is the overwhelmingly most common type of onychomycosis, is thought to originate from direct extension and invasion of dermatophytes infecting the plantar surface of the foot (tinea pedis) into the nail bed. Dermatophytomas are a feature seen in some DLSO infections and are characterized by thick adherent fungal masses within and under the nail plate. Dermatophytomas are particularly difficult to treat due to their fungal framework and composition.2
Until recently, traditional therapeutic options for DLSO have been comprised of mainly oral terbinafine and itraconazole, and although these medications are commonly prescribed, they have been associated with significant toxicities and drug-drug interactions. Dermatophytomas are often recalcitrant to even long courses of oral antifungal medications. In addition to severe infection and presence of dermatophytomas, other host factors associated with non-responsiveness to therapy include advanced age, peripheral vascular disease (PVD), immunosuppression, and concurrent psoriasis.3 Efinaconazole 10% solution is a new FDA approved topical medication indicated for treatment of DLSO. Here we report a case of an elderly patient with a history of PVD and a dermatophytoma caused by Trichophyton rubrum who was successfully treated with efinaconazole 10% solution. The dermatophytoma resolved within 3 months and the remaining onychomycosis infection was significantly improved and on course for a cure with time. This represents the first case of a dermatophytoma responding to a topical antifungal agent.

CASE REPORT

A 66-year-old man with a history of PVD, nonalcoholic steatohepatitis (NASH), and a distant history of tinea pedis treated with topical therapy, initially presented in 2012 for treatment of onychomycosis involving the left great toe. At that time, the patient had positive KOH scraping and culture positive for T. rubrum from his left great toe. The patient was initially treated for two months with oral terbinafine 250 mg daily, but this treatment was discontinued because of lack of efficacy and elevated liver function tests above the patient’s baseline. A second attempt of systemic treatment was made with one month of once weekly fluconazole 200mg; however this was discontinued after 4 weeks because of continued elevation of hepatic enzymes.
The patient continued to contact our office and expressed interest in participating in a clinical trial. Without adequate treatment, the patient’s onychomycosis progressed to include a dermatophytoma and he was thus excluded from participating in a clinical trial due to the severity of his infection.
In July 2014 the patient was brought back into clinic for further treatment as efinaconazole 10% solution had recently been approved for the treatment of onychomycosis. On presentation, the patient’s left great toe had a 9 mm wide yellow-brown streak extending from the distal nail edge to the proximal nail fold with associated moderate hyperkeratosis of the nail bed (Figure 1). All other toe and finger nails were unremarkable, and there was no evidence of concomitant tinea pedis.
The patient was prescribed efinaconazole 10% solution and was instructed to apply the medication once daily to the surface of the affected nail as well as to the hyponychium, as per label instructions. He was also advised to clip the onycholytic nail to better allow penetration of the medication into the nail bed and subungual space.
The patient followed up at week 12 and the dermatophytoma was completely resolved and 3.5 mm of new healthy nail was noted (Figure 2). The patient reported noting improvement as early as week 3, however no photos were taken prior to the