Factors that may affect the response of onychomycosis to oral antifungal therapy

Toe Web Infection: Epidemiology and Risk Factors in a Large Cohort Study

<b><i>Introduction:</i></b> Toe web infection (TWI) is a bacterial infection of the interdigital space. In most cases, the infection is caused by gram-negative bacteria, secondary to a chronic fungal infection (dermatophytosis). The typical presentation includes macerations and erosions in the interdigital space. Predisposing factors include interdigital tinea, hyperhidrosis, and humidity. <b><i>Objective:</i></b> The aim of this study was to characterize the TWI patient population and identify associated risk factors. <b><i>Methods:</i></b> We conducted a retrospective study of patients diagnosed with TWI from 2006 to 2020 at Sheba Medical Center, Israel. Collected data included patients’ demographics (age, sex, weight, and occupation), smoking pack-years, comorbidities, medications, and course of disease. <b><i>Results:</i></b> A total of 200 patients were diagnosed with TWI. The median age at diagnosis was 51 years. The majority of the patients were men (72.5%). The most common comorbidities were dyslipidemia, hypertension, diabetes, and ischemic heart disease. We found that 71.2% of patients were smokers, and 46.4% of patients had occupations that required closed-toe shoes. TWI incidence did not increase seasonally. Bilateral TWI was found in 50% of the patients, 33% had recurrent infections, and 20% had secondary cellulitis. <b><i>Conclusions:</i></b> Smoking and diabetes were more prevalent among TWI patients than in the general population, and there was a correlation between smoking and TWI recurrences. We identified risk factors for TWI to identify at-risk populations.

Continuous terbinafine and pulse itraconazole for the treatment of non-dermatophyte mold toenail onychomycosis

INTRODUCTION

Although dermatophytes are considered the predominant causative organisms in onychomycosis, non-dermatophyte mold (NDM) infections may be more prevalent than originally thought and may be more difficult to treat. There are limited data of oral antifungal efficacy in treating NDM onychomycosis.

METHOD

A retrospective chart review (2009-2016) was conducted in patients receiving continuous oral terbinafine or pulse itraconazole for toenail onychomycosis due to NDMs. Mycology results and percent nail affected were recorded with patient characteristics including demographics and concurrent diseases. Complete, clinical, and mycological cure were tabulated.

RESULTS

Data from 176 patients were collected. Mycological and complete cure rates for terbinafine (69.8% and 17%) and itraconazole (67.5% and 22%) were not significantly different from each other. Regardless of oral treatment, age (p = .013), baseline severity (p = .016), and presence of atherosclerosis (p = .040) or hyperlipidemia (p = .033) decreased the likelihood of mycological cure, while age decreased the likelihood of complete cure (p = .001).

CONCLUSION

Continuous terbinafine and pulse itraconazole were similar in efficacy for curing NDM onychomycosis. Age was the most consistent prognostic factor affecting likelihood of cure, with factors that may influence drug reaching the site of infection also decreasing likelihood of mycological cure.

Onychomycosis: Treatment and prevention of recurrence

Onychomycosis is a fungal nail infection caused by dermatophytes, nondermatophytes, and yeast, and is the most common nail disorder seen in clinical practice. It is an important problem because it may cause local pain, paresthesias, difficulties performing activities of daily living, and impair social interactions. The epidemiology, risk factors, and clinical presentation and diagnosis of onychomycosis were discussed in the first article in this continuing medical education series. In this article, we review the prognosis and response to onychomycosis treatment, medications for onychomycosis that have been approved by the US Food and Drug Administration, and off-label therapies and devices. Methods to prevent onychomycosis recurrences and emerging therapies are also described.

Clinico-aetiologic profile of Onychomycoses in a tertiary care centre in northeast India

Onychomycosis refers to fungal nail infection. Despite a clearly diseased appearance, it is often deemed a merely cosmetic problem of relatively minor importance. However, it may result in much psychological or occupational turmoil, diminished self-esteem and resulting reluctance for public interaction. A wide number of factors determine the treatment outcome and its prevalence varies greatly. Our study was conducted between January 2011 and December 2014 in northeast India. Of 243 patients presenting with nail abnormalities, 158 (65%) were positively diagnosed by either direct microscopy or culture or both. A distal lateral subungual infection was the most predominant clinical pattern observed, and the most frequent aetiological agents were dermatophytes, of which Trichophyton rubrum was predominant.

Improving Cure Rates in Onychomycosis

Background:

Onychomycosis is a persistent fungal nail infection that is notoriously hard to treat. Approximately 20% to 25% of patients with onychomycosis do not respond to treatment, and 10% to 53% of patients relapse. As such, successful treatment is imperative for long-term disease management.

Objective:

To identify ways to improve cure rates for onychomycosis.

Method:

The literature on onychomycosis treatment and recurrence was reviewed to summarize treatment approaches and suggest strategies to increase cure rates.

Results and Conclusion:

To improve treatment success in onychomycosis, we suggest the following measures be followed: (1) onychomycosis must be correctly diagnosed, (2) the treatment regimen should be tailored to the individual patient, (3) the efficacy of antifungals must be maximized, and (4) recurrence must be prevented.

End points in dermatologic clinical trials: A review for clinicians

Clinical trials are critical for the development of new therapies in dermatology, and their results help determine US Food and Drug Administration (FDA) approval and guide care. Of special relevance is the clinical trial efficacy end point, the metric from which statistically significant outcome is derived. Clinicians' understanding of a clinical trial's end point is necessary for critical analysis of the trial results and for applying those results to daily practice. This review provides practical knowledge and critical evaluation of end points used in treatment approvals by the FDA. The end points for actinic keratosis, acne vulgaris, atopic dermatitis, onychomycosis, and cutaneous ulcer serve as examples.

Controlled-release injectable containing terbinafine/PLGA microspheres for onychomycosis treatment

Controlled-release drug delivery systems based on biodegradable polymers have been extensively evaluated for use in localized drug delivery. In the present study, intralesionally injectable poly (lactide-co-glycolide) (PLGA) microspheres for controlled release of terbinafine hydrochloride (TH) was developed for treating fungal toe/finger nail infections. TH-PLGA microspheres were formulated using O/W emulsification and modified solvent extraction/evaporation technique. Microspheres were evaluated for particle size and size distribution, encapsulation efficiency, surface, and morphology. The in vitro drug release profile was studied in aqueous media as well as in 1% agar gel. Microspheres system was also evaluated in excised cadaver toe model, and extent of TH accumulation in nail bed, nail plate, and nail matrix was measured at different time points. Microspheres were found to provide consistent and sustained TH release. Intralesional administration of controlled-release microspheres can be a potential alternative mode of treating fungus-infected toe and/or finger nails.

A comparative study of dermatophyte infections in Bursa, Turkey

A total of 555 specimens from 372 patients with symptoms compatible with superficial mycosis were included in this study. Those from patients clinically diagnosed as having dermatomycosis were thoroughly investigated by mycological examinations in the laboratory, including microscopic studies of KOH mounts and cultivation of the samples in culture. The results of this study and a previous study in our hospital conducted in 1980 were compared with respect to clinical presentation and etiological agents. Onychomycosis was the most common clinical form of dermatomycoses, and Trichophyton rubrum was the most common pathogen in this study.

How to improve cure rates for the management of onychomycosis

To improve the treatment of onychomycosis clinicians need to identify correctly the causative organism, choose a therapy that is effective against the pathogen, and take into consideration the pharmacokinetics (eg, bioavailability, drug interactions) of the oral agent. In addition, variations of the standard regimens may need to be considered (ie, booster or supplemental therapy). To reduce the recurrence of onychomycosis, once mycologic cure has been achieved, clinicians should educate their patients about proper foot care. Familiarity with the symptoms and signs of tinea pedis and onychomycosis may enable patients to seek appropriate care when the disease is at an early stage.

Guidelines for treatment of onychomycosis

These guidelines for management of onychomycosis have been prepared for dermatologists on behalf of the British Association of Dermatologists. They present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation.

Single-blind, randomized, prospective study on terbinafine and itraconazole for treatment of dermatophyte toenail onychomycosis in the elderly

BACKGROUND

The 2 most common agents used to treat dermatophyte onychomycosis of the toe are terbinafine (continuous) and itraconazole (pulse). Although comparative studies have been performed evaluating the efficacy of these 2 agents in adults, no such studies have been reported specifically in the elderly subset.

OBJECTIVE

This prospective, randomized, single-blind, non--industry-sponsored, comparative study evaluated the efficacy and safety of terbinafine (continuous) and itraconazole (pulse) therapies in the treatment of dermatophyte onychomycosis of the toe in the elderly population.

METHODS

Elderly patients (> or =60 years old) with dermatophyte onychomycosis of at least 1 great toe were randomly assigned to receive either terbinafine 250 mg/day for 12 weeks or itraconazole (pulse) 200 mg twice a day for 1 week, given for 3 pulses. At month 6 from the start of therapy, if there was less than 50% reduction in the affected nail plate area compared with baseline, or if there was less than 3 mm outgrowth of unaffected nail plate as measured in midline, then patients who had been administered terbinafine (continuous) therapy were given an extra 4 weeks of the drug (total of 16 weeks of therapy), and those who had received itraconazole (pulse) therapy were given an extra pulse (fourth pulse). Patients were evaluated at 1.5, 3, 6, 12, and 18 months from the start of therapy. The efficacy measures included mycologic cure rate and clinical efficacy (mycologic cure plus clinical cure or clinical improvement so that 10% or less of nail plate was clinically involved).

RESULTS

There were 101 elderly patients enrolled in the study with 50 and 51 patients receiving terbinafine and itraconazole, respectively. The terbinafine group consisted of 28 men and 22 women, age (mean +/- standard error [SE]) 68.0 +/- 0.9 years, duration of onychomycosis (mean +/- SE) 18.2 +/- 1.4 years, number of nails involved (mean +/- SE) 5.5 +/- 0.5, and percent baseline nail plate area involved (mean +/- SE) 67.5% +/- 4.2%. The corresponding figures for the itraconazole (pulse) group were 24 men and 27 women, age (mean +/- SE) 68.8 +/- 0.8 years, duration of onychomycosis (mean +/- SE) 16.1 +/- 1.7 years, number of nails involved (mean +/- SE) 6.0 +/- 0.7, and percent baseline nail plate area involved (mean +/- SE) 74.9% +/- 3.8%, respectively, with no significant difference between the groups. At month 6, the number of patients that required an extra 4 weeks of terbinafine in the allylamine group or an extra itraconazole pulse in the triazole group was 13 of 50 and 23 of 51, respectively. The mycologic cure rate and clinical efficacy at 18 months from the start of therapy for the terbinafine group were 64.0% and 62.0%, respectively. The corresponding figures for the itraconazole (pulse) group were 62.7% and 60.8%, respectively, with no significant difference between the 2 groups. There were no dropouts during therapy. For both groups the drug appeared safe with no significant adverse events (AEs) or clinically significant laboratory abnormalities. All the AEs were mild and transient. There was high compliance with both regimens.

CONCLUSIONS

In the elderly, for the treatment of dermatophyte toe onychomycosis, both terbinafine (continuous) and itraconazole (pulse) therapies are effective, safe, and associated with high compliance.

Ciclopirox nail lacquer solution 8% in the 21st century

Ciclopirox nail lacquer solution 8% has been shown to be effective in the treatment of dermatophyte onychomycosis of mild to moderate severity Other studies report the effectiveness of ciclopirox nail lacquer in onychomycosis caused by Candida sp and nondermatophyte molds. Ciclopirox nail lacquer may also be valuable in the treatment of early cases of reinfection/relapse. Ciclopirox nail lacquer solution 8% may be an important adjunct to oral antifungal therapy in certain presentations that might be poorly responsive to oral antifungal therapy alone (eg, lateral onychomycosis, longitudinal spike, dermatophytoma, and extensive onycholysis). In some cases, surgical therapies may need to be considered in addition to, or in preference to, topical nail lacquer treatment. The use of ciclopirox nail lacquer solution 8% as an adjunct to oral antifungal therapy may widen the spectrum of activity of the combination because of the broad spectrum of coverage provided by the lacquer. The use of combination therapy may be synergistic in terms of efficacy, enabling a reduction in the duration and cumulative dosage of oral therapy. This could result in a decrease in the frequency and severity of systemic adverse effects associated with the oral antimycotics and the need to be vigilant about drug interactions. Studies need to be conducted to determine the place of combination oral and topical lacquer therapy in the management of onychomycosis.

Nail disorders

Nail lesions can be related to a number of disease states. These may be intrinsic to the nail, caused by infection, or reflect systemic disease. Careful history and examination often is necessary for accurate diagnosis. Anatomy and gross changes of the nail are reviewed. The diagnosis and treatment of disease process such as psoriasis, lichen planus, paronychia, onychomycosis, myxoid cysts, and pincer nails are reviewed.

Onychomycosis in the elderly

Onychomycosis is found more frequently in the elderly, and in more males than females. Onychomycosis of the toes is usually caused by dermatophytes, most commonly Trichophyton rubrum and T. mentagrophytes. The most common clinical presentations are distal and lateral subungual onychomycosis (which usually affects the great/first toe) and white superficial onychomycosis (which generally involves the third/fourth toes). Only about 50% of all abnormal-appearing nails are due to onychomycosis. In the remainder, trauma to the nail, psoriasis and conditions such as lichen planus should be considered in the differential diagnosis. Therefore, the clinical impression of onychomycosis should be confirmed by mycological examination, whenever possible. The management of onychomycosis may include no therapy, palliative treatment with mechanical or chemical debridement, topical antifungal therapy, oral antifungal agents or a combination of treatment modalities. In the US, the only new oral agents approved for treatment of onychomycosis are terbinafine and itraconazole. Fluconazole is approved for onychomycosis in some other countries. Ciclopirox nail lacquer has recently been approved in the US for the treatment of onychomycosis. In some other countries topical agents such as amorolfine are also used. Griseofulvin and ketoconazole are no longer preferred for the treatment of onychomycosis. The new oral antifungal agents are effective and well tolerated in the elderly. Patient selection should be based on the history (including systems review and medication record), examination and baseline monitoring, if indicated. Laboratory monitoring during therapy for onychomycosis varies among physicians. A combination of removal of the diseased nail plate or local measures and oral antifungal therapy may be optimal in certain instances, e.g. when lateral onychomycosis or dermatophytoma are present. For dermatophyte toe onychomycosis the recommended duration of therapy with terbinafine is 250 mg/day for 12 weeks. For itraconazole (pulse) the regimen is 200 mg twice daily for 1 week on, 3 weeks off, repeated for 3 consecutive pulses and with fluconazole the regimen is 150 to 300 mg once weekly given for a usual range of 6 to 12 months or until the nail plate has grown out. In some instances, if extra therapy is required, one suggestion is that 4 weeks of terbinafine or an extra pulse of itraconazole are given between months 6 and 9 from the start of therapy. Once cure has been achieved, it is important to counsel patients on the strategies of reducing recurrence of disease.

A risk-benefit assessment of the newer oral antifungal agents used to treat onychomycosis

The newer antifungal agents itraconazole, terbinafine and fluconazole have become available to treat onychomycosis over the last 10 years. During this time period these agents have superseded griseofulvin as the agent of choice for onychomycosis. Unlike griseofulvin, the new agents have a broad spectrum of action that includes dermatophytes, Candida species and nondermatophyte moulds. Each of the 3 oral antifungal agents, terbinafine, itraconazole and fluconazole, is effective against dermatophytes with relatively fewer data being available for the treatment of Candida species and nondermatophyte moulds. Itraconazole is effective against Candida onychomycosis. Terbinafine may be more effective against C. parapsilosis compared with C. albicans; furthermore with Candida species a higher dose of terbinafine or a longer duration of therapy may be required compared with the regimen for dermatophytes. The least amount of experience in treating onychomycosis is with fluconazole. Griseofulvin is not effective against Candida species or the nondermatophyte moulds. The main use of griseo-fulvin currently is to treat tinea capitis. Ketoconazole may be used by some to treat tinea versicolor with the dosage regimens being short and requiring the use of only a few doses. The preferred regimens for the 3 oral antimycotic agents are as follows: itraconazole - pulse therapy with the drug being administered for 1 week with 3 weeks off treatment between successive pulses; terbinafine - continuous once daily therapy; and fluconazole - once weekly treatment. The regimen for the treatment of dermatophyte onychomycosis is: itraconazole - 200mg twice daily for I week per month x 3 pulses; terbinafine - 250 mg/day for 12 weeks; or, fluconazole - 150 mg/wk until the abnormal-appearing nail plate has grown out, typically over a period of 9 to 18 months. For the 3 oral antifungal agents the more common adverse reactions pertain to the following systems, gastrointestinal (for example, nausea, gastrointestinal distress, diarrhoea, abdominal pain), cutaneous eruption, and CNS (for example, headache and malaise). Each of the new antifungal agents is more cost-effective than griseofulvin for the treatment of onychomycosis and is associated with high compliance, in part because of the shorter duration of therapy. The newer antifungal agents are generally well tolerated with drug interactions that are usually predictable.

Developments in the treatment of nail psoriasis, melanonychia striata, and onychomycosis. A review of the literature

Nail psoriasis, melanonychia striata, and onychomycosis are relatively common nail disorders that have generated much research into their pathophysiology and treatment. The authors hope this discussion of the recent therapeutic developments for treating these disorders will not only inform but will also inspire further investigation so that therapeutic advances may continue.