Risk Factors and Comorbidities for Onychomycosis: Implications for Treatment with Topical Therapy

A number of comorbidities and risk factors complicate the successful management of onychomycosis. Underlying conditions and patient characteristics, such as tinea pedis, age, and obesity, contribute to risk, whereas comorbidities, such as diabetes and psoriasis, can increase susceptibility to the disease. There are limited data on treatment effectiveness in these patients. Here, the authors review post hoc analyses of efinaconazole topical solution, 10%, in mild-to-moderate onychomycosis and present new data in terms of age and obesity. The only post hoc analysis to report significant differences so far is gender, where female patients do much better; however, the reasons are unclear. The authors report significant differences in terms of efficacy in obese patients who do not respond as well as those with normal body mass index (P=0.05) and in patients who have their co-existing tinea pedis treated compared to those in whom co-existing tinea pedis was not treated (P=0.025). Although there is a trend to reduced efficacy in older patients and those with co-existing diabetes, differences were not significant. More research is needed in onychomycosis patients with these important risk factors and comorbidities to fully evaluate the treatment challengse and possible solutions.Onychomycosis is a common problem in dermatology practice that can result in significant morbidity.1,2 Successful treatment has been difficult because of slow growth of the nail; patient comorbidities, such as diabetes, peripheral vascular disease, and psoriasis; and reluctance of prescribers and patients to prescribe or take oral medications because of “perceived” toxicity issues.The disease can have a major impact on the individual and other family members.3-5 Dystrophic nails can cause embarrassment, affecting a patient’s self-esteem, and may have a greater impact on quality of life (QoL) than the severity of the disease itself.6 Thickened nails can also be painful, causing discomfort in walking and affecting other aspects of daily living.3A number of underlying conditions, such as tinea pedis, nail damage, and nail psoriasis can contribute to risk as well as characteristics such as age and obesity. Underlying comorbidities, such as diabetes,7,8 cancer,7,9 immunodeficiency,10 or peripheral arterial disease,11 can increase susceptibility to onychomycosis.7 An inherited genetic predisposition to infection has also been identified.12Clinical trials provide guidance on likely treatment outcomes in these patients at risk. However, some comorbid conditions (i.e., peripheral vascular disease) can be exclusion criteria, many trials were not set up to specifically study certain comorbidities, and the demographics and disposition of patients who visit dermatology and podiatry practices can be very different from those enrolled in clinical trials.Recently, a number of post hoc analyses have been published on the use of efinaconazole topical solution, 10%, in the treatment of mild-to-moderate onychomycosis. Where data exist, it is the authors’ intention to review the findings in terms of the implications for successful treatment outcomes. In addition, they present new data with efinaconazole in terms of age and obesity.Aging is the most common risk factor for onychomycosis, most likely due to poor peripheral circulation, longer exposure to pathogenic fungi, repeated nail trauma, suboptimal immune function, and slower nail growth.13 In addition, various medical conditions more common in the elderly increase the risk of comorbid onychomycosis. Surveys suggest that overall the incidence is much higher in adults than in children, afflicting 0.6 percent of children under the age of 18 years, approximately 10 to 20 percent of adults and 15 to 40 percent of elderly people.14-16 However, prevalence rates do not necessarily correlate with consultations. Not all of the patients we see with onychomycosis are elderly. This could be attributed to the fact that onychomycosis may be considered a cosmetic problem by the younger patients who are more conscious of their appearance coming forward for therapy. The increased incidence in the younger population could also be due to their exposure to occupation-related trauma predisposing them to onychomycosis or the more common use of occlusive footwear.     

Treatment of Onychomycosis with Efinaconazole 10% Topical Solution and Quality of Life

Objective: To evaluate the benefits of efinaconazole topical solution, 10% on quality of life in onychomycosis patients. Methods: An analysis of 1,655 patients, aged 18 to 70 years, randomized to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled, 48-week studies evaluating safety and efficacy. The primary endpoint was complete cure rate (0% clinical involvement of target toenail, and both negative potassium hydroxide examination and fungal culture); clinical improvement defined as ≤ 10-percent improvement in nail involvement both at Week 52. Quality of life was assessed using a validated OnyCOE-t™ questionnaire. Improvement in quality of life was compared in those patients clinically and not clinically improved. Results: Efinaconazole topical solution, 10%, was significantly more effective than vehicle irrespective of QoL domain. Greatest improvement in mean score was seen in those domains with the lowest baseline scores. All mean scores in the group considered to have clinically improved with efinaconazole exceeded 80.0 at Week 52. Mean treatment satisfaction scores with efinaconazole in those patients who were clinically improved increased from 79.9 (Week 24) to 89.2 (Week 52), compared to a corresponding drop in those patients considered not improved from 65.3 to 58.0. The correlation between change in percent affected nail and change in mean domain scores was significant with efinaconazole for all domains. Limitations: A period of 52 weeks may be too brief to evaluate improvement in quality of life in onychomycosis patients. Some of the questions in the OnyCOE-t questionnaire may be more relevant than others to the study population and the onychomycosis population as a whole. Conclusion: Once-daily efinaconazole topical solution, 10%, provided statistically greater improvement in all aspects of quality of life compared to vehicle. Improvement was most marked in those patients considered clinically improved and correlated with a change in percent affected nail.Onychomycosis is a common, growing problem in dermatology practice, most frequently seen in toenails and difficult to treat successfully.1,2 It is a progressive disease, not self-healing, and occasionally the source of more widespread infection.3 Many patients suffer long-standing disease affecting several toenails.4Onychomycosis can have significant impact on the individual and other family members.5-7 The unsightly appearance of the toenail is a real concern, and often the initial reason why patients seek medical help. Indeed, the appearance of the toenail may have a more significant impact on quality of life (QoL) than the severity of the disease.8It can disrupt daily activities, negatively impact QoL, and occasionally results in significant pain and discomfort.5 The symptoms of onychomycosis and their impact on personal appearance are important determinants of patients’ perceptions of their own health. The effect of onychomycosis is greater on psychosocial than physical functioning and is directly related to the extent of nail involvement.9 Data are conflicting as to whether nail appearance or disease severity are the more important from a patient’s perspective of QoL. Area alone does not necessarily predict disease severity, and a thick nail with limited involvement may have a poor prognosis.10 Commonly reported psychosocial factors include embarrassment, low self-esteem, and social withdrawal.11The true burden of disease is unknown, but patients’ desire to have their affected nails cured is clear.5,12 Patient surveys have noted a substantial impact in several QoL domains including physical functioning (associated with foot-related activities), social functioning (affected by pain and discomfort restricting social activities and embarrassment associated with the nail appearance), and emotional well-being affected by negative feedback received from their social environment.13-15A number of disease-targeted questionnaires have been developed to assess the impact of onychomycosis and its treatment on health-related QoL. The instruments differ considerably in the extent to which they have been psychometrically tested. The generic and disease-targeted scales of most of the available questionnaires exhibit poor variability, which may limit their responsiveness to clinically important change.9 As a result; there is a lack of data to demonstrate the true QoL response to onychomycosis treatment.Improvements in QoL have been reported to correlate with the improvement or cure of infected nails.16-20 As a result, patients satisfied with their treatment had better health-related QoL;21 although patients with recurrent disease had significantly poorer QoL than those with onychomycosis for the first time that had not previously been treated.22 A significant portion of patients feel unattractive and stigmatized by onychomycosis and antimycotic therapy has been reported to result in a significant reduction of stigmatization of about 60 percent from baseline levels.23A toenail-specific questionnaire, the OnyCOE-t™, and objective clinical measures have been used to assess responsiveness of patients in a prospective onychomycosis trial.24,25 Patients were treated with terbinafine (± aggressive debridement) and comparisons made between those patients who were judged to have clinically improved and those who had not improved.The objective of this current study was to utilize this validated OnyCOE-t questionnaire to assess differences in QoL response in onychomycosis patients following treatment with efinaconazole topical solution, 10%, or vehicle. In addition, the authors compared results in those patients who were considered clinically improved (≤10% nail involvement) with those who were not clinically improved at Week 52 following active treatment, to assess the clinical meaningfulness of their results.     

Onychotillomania: 2 case reports

Onychotillomania is an uncommon condition characterized by self-destruction of the fingernails and/or toenails by compulsive manipulation. We report 2 cases of onychotillomania with differing presentations in a young man and in an older man. Onychotillomania may be a form of obsessive-compulsive disorder (OCD), and we discuss the psychologic factors and current treatments for this condition.     

Epidemiologic surveillance of cutaneous fungal infection in the United States from 1999 to 2002

BACKGROUND: Cutaneous fungal infections are common in the United States, and causative organisms include dermatophytes, yeasts, and nondermatophyte molds. These organisms are in constant competition for their particular environmental niche, often resulting in the emergence of one or more predominant pathogens and displacement of other less competitive species. Changes in the incidence of fungal pathogens can be followed from laboratory culture results of infected cutaneous tissues over time. These data can be used to ascertain past and present trends in incidence, predict increases in antifungal resistance and the adequacy of our current pharmacologic repertoire, and provide insight into future developments. OBJECTIVE: This study identifies epidemiologic trends and the predominant organisms causing superficial fungal infections in the United States. METHODS: A total of 15,381 specimens were collected from clinically suspected tinea corporis, tinea cruris, tinea capitis, tinea faciei, tinea pedis, tinea manuum, and finger and toe onychomycosis from 1999 through 2002. Specimens were submitted to the Center for Medical Mycology in Cleveland, Ohio, for fungal culture and identification, and the incidence of each species was calculated. RESULTS: Dermatophytes remain the most commonly isolated fungal organisms except from clinically suspected finger onychomycosis, in which case Candida species comprise >70% of isolates. Trichophyton rubrum remains the most prevalent fungal pathogen, and increased incidence of this species was observed in finger and toe onychomycosis, tinea corporis and tinea cruris, tinea manuum, and tinea pedis. As the causal agent of tinea capitis, T tonsurans continues to increase in incidence, achieving near exclusionary proportions in the United States. CONCLUSION: Consideration of the current epidemiologic trends in the incidence of cutaneous fungal pathogens is of key importance to investigational efforts, diagnosis, and treatment.     

Successful Treatment of Fluconazole-Resistant Oropharyngeal Candidiasis by a Combination of Fluconazole and Terbinafine

Increasing incidence of resistance to conventional antifungal therapy has demanded that novel therapies be introduced. Recent in vitro studies have shown that combinations involving azoles and allylamines may be effective in inhibiting fluconazole-resistant fungi. In this report, we describe the case of a 39-year-old woman who presented with white patches on her buccal mucosa, tongue, and palate with a bright erythematous erosive base. A fungal culture revealed Candida albicans. The patient failed to respond to the initially prescribed fluconazole therapy. Failure of therapy can be attributed to a developed resistance to fluconazole from the patient’s intermittent use of this antifungal agent at varying dosages for the preceding 2 years due to a diagnosis of onychomycosis. In vitro testing of the culture from the patient showed elevated MICs of fluconazole, itraconzole, and terbinafine (MICs were 32, 0.5, and 64 μg/ml, respectively). Our goal was to combine therapies of fluconazole and terbinafine in an attempt to clear the fungal infection. Impressively, this combination resulted in the clearing of the clinical symptoms and the patient has successfully been asymptomatic for more than 12 months posttreatment.     

A novel foam formulation of ketoconazole 2% for the treatment of seborrheic dermatitis on multiple body regions

BACKGROUND: A novel topical foam formulation of ketoconazole has been developed for use on the scalp, body, and face. OBJECTIVE: To evaluate the efficacy and safety of twice-daily treatment with ketoconazole 2% foam for seborrheic dermatitis on the scalp, body, and face. METHODS: One thousand one hundred sixty-two subjects, aged 12 years or older, with mild to severe seborrheic dermatitis were randomized to receive ketoconazole foam (n=427), vehicle foam (n=420), ketoconazole cream (n=210), or vehicle cream (n=105) twice daily for 4 weeks. The primary endpoint was the proportion of subjects achieving an Investigator's Static Global Assessment score of 0 or 1 at week 4 (treatment success). RESULTS: A significantly greater percentage of subjects achieved treatment success using ketoconazole foam than vehicle foam (56% and 42%, respectively; P<.0001); ketoconazole foam was shown to be equivalent to ketoconazole cream. Ketoconazole foam was well-tolerated with a low incidence of treatment-related adverse events (14%; 59/427). CONCLUSION: Ketoconazole foam 2% is a safe, effective, and versatile formulation for use on the scalp, body, and face for the treatment of seborrheic dermatitis in patients aged 12 years or older.