Effect of onychomycosis on quality of life

Permeation studies of novel terbinafine formulations containing hydrophobins through human nails in vitro

Existing treatments of onychomycosis are not satisfactory. Oral therapies have many side effects and topical formulations are not able to penetrate into the human nail plate and deliver therapeutical concentrations of active agent in situ. The purpose of the present study was to determine the amount of terbinafine, which permeates through the human nail plate, from liquid formulations containing enhancers, namely hydrophobins A-C in the concentration of 0.1% (w/v). The used reference solution contained 10% (w/v) of terbinafine in 60% (v/v) ethanol/water without enhancer. Permeability studies have been performed on cadaver nails using Franz diffusion cells modified to mount nail plates and filled with 60% (v/v) ethanol/water in the acceptor chamber. Terbinafine was quantitatively determined by HPLC. The amount of terbinafine remaining in the nail was extracted by 96% ethanol from pulverized nail material after permeation experiment and presented as percentage of the dry nail weight before the milling test. Permeability coefficient (PC) of terbinafine from reference solution was determined to be 1.52E-10 cm/s. Addition of hydrophobins improved PC in the range of 3E-10 to 2E-9 cm/s. Remaining terbinafine reservoir in the nail from reference solution was 0.83% (n=2). An increase of remaining terbinafine reservoir in the nail was observed in two out of three tested formulations containing hydrophobins compared to the reference. In all cases, known minimum inhibitory concentration of terbinafine for dermatophytes (0.003 microg/ml) has been exceeded in the acceptor chamber of the diffusion cells. All tested proteins (hydrophobins) facilitated terbinafine permeation after 10 days of permeation experiment, however one of them achieved an outstanding enhancement factor of 13.05 compared to the reference. Therefore, hydrophobins can be included in the list of potential enhancers for treatment of onychomycosis.

Burden of skin diseases

Skin diseases are among the most common health problems worldwide and are associated with a considerable burden. The burden of skin disease is a multidimensional concept that encompasses psychological, social and financial consequences of the skin disease on the patients, their families and on society. Chronic and incurable skin diseases, such as psoriasis and eczema, are associated with significant morbidity in the form of physical discomfort and impairment of patients' quality of life; whereas malignant diseases, such as malignant melanoma, carry substantial mortality. With the availability of a wide range of health status and quality-of-life measures, the effects of most skin diseases on patients' lives can be measured efficiently. The aim of this review is to present some of the published data in order to highlight the magnitude of the burden associated with some common skin diseases and also to suggest ways to quantify this burden of skin disease.

Slowly adapting mechanoreceptors in the borders of the human fingernail encode fingertip forces

There are clusters of slowly adapting (SA) mechanoreceptors in the skin folds bordering the nail. These "SA-IInail" afferents, which constitute nearly one fifth of the tactile afferents innervating the fingertip, possess the general discharge characteristics of slowly adapting type II (SA-II) tactile afferents located elsewhere in the glabrous skin of the human hand. Little is known about the signals in the SA-IInail afferents when the fingertips interact with objects. Here we show that SA-IInail afferents reliably respond to fingertip forces comparable to those arising in everyday manipulations. Using a flat stimulus surface, we applied forces to the finger pad while recording impulse activity in 17 SA-IInail afferents. Ramp-and-hold forces (amplitude 4 N, rate 10 N/s) were applied normal to the skin, and at 10, 20, or 30 degrees from the normal in eight radial directions with reference to the primary site of contact (25 force directions in total). All afferents responded to the force stimuli, and the responsiveness of all but one afferents was broadly tuned to a preferred direction of force. The preferred directions among afferents were distributed all around the angular space, suggesting that the population of SA-IInail afferents could encode force direction. We conclude that signals in the population of SA-IInail afferents terminating in the nail walls contain vectorial information about fingertip forces. The particular tactile features of contacted surfaces would less influence force-related signals in SA-IInail afferents than force-related signals present in afferents terminating in the volar skin areas that directly contact objects.

Current management of onychomycosis

Onychomycosis is the most common single cause of nail dystrophy and has a marked impact on quality of life. The availability of newer topical and systemic antifungal agents has improved our ability to effectively treat this condition. This article will review the most commonly used therapies and discuss the relative advantages and disadvantages of different treatment strategies.

Nail swelling as a pre-formulation screen for the selection and optimisation of ungual penetration enhancers

INTRODUCTION

Targeting drug treatment to fungal infections that reside within or below the nail plate is problematic due to the highly restrictive barrier of the human nail. To optimise topical formulations for ungual drug delivery, inclusion of an effective penetration enhancer (PE) is imperative. At present, in vitro nail permeation studies can take weeks or months in order to obtain any meaningful data because the lack of a simple in vitro model to identify and develop nail PEs makes the selection and optimisation of novel PEs an empirical and inefficient process. The aim of this study was to compare three methods for pre-formulation screening of putative ungual PEs and then to select the most suitable technique for screening candidates that may enhance the permeation of therapeutic agents through the human nail.

METHODS

Three screening techniques were evaluated; nail swelling (weight increase of human nail clippings), horse hoof swelling (weight increase of horse hoof clippings) and nail penetration of a radiolabelled permeability probe. Four test PEs were evaluated using each screening method and nail swelling was identified as a simple, rapid, economic, relevant and reliable technique. This screen was then used to evaluate 20 potential PEs. Thioglycolic acid (TA), hydrogen peroxide (H(2)O(2)) and urea H(2)O(2) produced the greatest nail weight increases; 71.0+/-4.6%, 69.2+/-6.6%, and 69.0+/-9.9 respectively. To confirm the relationship between human nail swelling and altered ungual barrier function, a permeation study was performed in human nails using caffeine as a model penetrant.

RESULTS AND DISCUSSION

Human nails pre-treated with TA in vitro had a 3.8-fold increase in caffeine flux compared to the control (TA-free solution). This study illustrated the potential to use human nail clipping swelling as a surrogate marker of PE activity for topical ungual drug delivery.

Evaluation of quality of life in patients with toenail onychomycosis by Polish version of an international onychomycosis-specific questionnaire

BACKGROUND

Onychomycosis is the most frequent nail disease, which could impair the patient's quality of life.

OBJECTIVE

The present study was undertaken to evaluate the impact of toenail onychomycosis on quality of life among Polish population.

PATIENTS AND METHODS

Three thousand nine-hundred and four (3904: 2269 females and 1635 males) individuals fulfilled an international onychomycosis-specific quality-of-life questionnaire consisting of statements regarding social, emotional and symptoms problems. All patients had toenail onychomycosis confirmed by the positive direct microscopic examination and/or by the positive mycologic culture. Seven hundred and sixty-seven patients simultaneously had fingernail onychomycosis. All patients were divided into subgroups according to sex, age, education level, place of living, type of onychomycosis, number of involved toenails, fingernails involvement, duration of illness and previously used antimycotic therapy.

RESULTS

Most of the patients demonstrated significantly reduced quality of life. The degree of life impairment varied between analysed subgroups. Patients with more advanced toenail onychomycosis and with fingernail involvement were more seriously affected. Both social and emotional impairments were more pronounced in female than in male patients, although there were no differences according to symptoms. Moreover, patients with better educational level and people living in towns or cities were more emotionally and socially affected by onychomycosis, although people living in the country or with poorer education level presented with significantly more severe symptoms.

CONCLUSIONS

Toenail onychomycosis is still a serious medical problem, which can significantly reduce the patient's quality of life.

Nail changes due to docetaxel--a neglected side effect and nuisance for the patient

GOALS OF WORK

The objective of this study is to estimate the frequency and severity of nail changes due to treatment with the cytotoxic drug docetaxel and, secondly, to estimate how the nail changes effects the patients cosmetically and functionally in their daily activities. Finally, we want to clarify whether fungal infection could contribute in causing the nail changes.

MATERIALS AND METHODS

Fifty-five patients with metastatic breast cancer in treatment with the cytotoxic drug docetaxel participated in the study. They filled out two questionnaires about their experience with possible nail changes. The frequency of fungal infection was examined. At each of the two visits, information about the number of treatment cycles, dose of docetaxel the patient received, frequency of lymph oedema, previous treatment with chemotherapy and the reason of discontinuance of treatment, if relevant, were registered. Finally, photos were taken to document the nail changes in hands and feet.

MAIN RESULTS

Fifty-eight percent had some degree of nail changes and an increase to 88.5% was seen after three additional cycles. A large proportion of the patients experienced the nail changes as a cosmetic nuisance, and more than 32% had functional problems.

CONCLUSION

Nail changes occur more frequently than previous studies have shown. Furthermore, our study indicates that the nail changes are affecting a large proportion of the patients, both cosmetically and functionally, which may lead to a decrease in their quality of life. No significant association was found according to the possible relation between nail changes and fungal infection.

Toenail onychomycosis: current and future treatment options

Onychomycosis is a common disease affecting as much as 8% of the general population. Treatment of onychomycosis is challenging, complicated by low cure rates and relatively high relapse rates. This paper reviews the efficacy of current oral, topical, and surgical treatment options. Currently, the treatment of choice for toenail onychomycosis is oral terbinafine because of its high efficacy, low relapse rates, and cost-effectiveness. Oral itraconazole or fluconazole could be considered for infections caused by Candida. Topical therapies may be a useful adjunct to these systemic therapies, but are less effective when used alone. More research is needed to determine the best measures for preventing reinfection.

Spores, sporodochia and fomites in onychomycosis

Onychomycosis is a frequent infection. Contagion rarely depends on direct contamination, but rather on environmental propagule dispersion including the intervention of fomites. The potential release of fungal cells in the environment from the affected nails has not been thoroughly studied. Observations made by histomycology suggest that arthroconidia and chlamydoconidia issued from invading fungi can be involved. In addition, the sporodochium, which is an exophytic fungal ball, may be attached underneath the distal free edge of some onychomycoses. It might represent an important source of fungal propagules in patients with poor nail trimming.

The OnyCOE-t questionnaire: responsiveness and clinical meaningfulness of a patient-reported outcomes questionnaire for toenail onychomycosis

Background

This research was conducted to confirm the validity and reliability and to assess the responsiveness and clinical meaningfulness of the OnyCOE-t^™, a questionnaire specifically designed to measure patient-reported outcomes (PRO) associated with toenail onychomycosis.

Methods

504 patients with toenail onychomycosis randomized to receive 12 weeks of terbinafine 250 mg/day with or without target toenail debridement in the IRON-CLAD^® trial completed the OnyCOE-t™ at baseline, weeks 6, 12, 24, and 48. The OnyCOE-t™ is composed of 6 multi-item scales and 1 single-item scale. These include a 7-item Toenail Symptom assessment, which comprises both Symptom Frequency and Symptom Bothersomeness scales; an 8-item Appearance Problems scale; a 7-item Physical Activities Problems scale; a 1-item Overall Problem scale; a 7-item Stigma scale; and a 3-item Treatment Satisfaction scale. In total, 33 toenail onychomycosis-specific items are included in the OnyCOE-t™. Clinical data, in particular the percent clearing of mycotic involvement in the target toenail, and OnyCOE-t™ responses were used to evaluate the questionnaire's reliability, validity, responsiveness, and the minimally clinical important difference (MCID).

Results

The OnyCOE-t™ was shown to be reliable and valid. Construct validity and known groups validity were acceptable. Internal consistency reliability of multi-item scales was demonstrated by Cronbach's alpha > .84. Responsiveness was good, with the Treatment Satisfaction, Symptom Frequency, Overall Problem, and Appearance Problem scales demonstrating the most responsiveness (Guyatt's statistic of 1.72, 1.31, 1.13, and 1.11, respectively). MCID was evaluated for three different clinical measures, and indicated that approximately an 8.5-point change (on a 0 to 100 scale) was clinically meaningful based on a 25% improvement in target nail clearing.

Conclusion

The OnyCOE-t™ questionnaire is a unique, toenail-specific PRO questionnaire that can be used with confidence in future studies of toenail onychomycosis. MCID was evaluated for three different clinical measures, and indicated that approximately a 7-point change (on a 0 to 100 scale) was clinically meaningful based on a 12.5% improvement in target nail clearing.

Brittle nail syndrome: a pathogenesis-based approach with a proposed grading system

Brittle nail syndrome is a heterogeneous abnormality, characterized by increased fragility of the nail plate. Brittle nails affect about 20% of the population and women are affected twice as frequently as men. The vast majority of patients experience brittle nails as a significant cosmetic problem and a substantial number indicate that these nail abnormalities are painful, impair daily activities, and may have a negative impact on occupational abilities. Pathogenic factors leading to brittle nails are factors that impair intercellular adhesion of the corneocytes of the nail plate or factors that cause a pathologic nail formation by involving the matrix. Clinical features of brittle nail syndrome are onychoschizia and onychorrhexis: the impairment of intercellular adhesive factors of the nail plate is expressed as onychoschizia, whereas the involvement of the nail matrix is expressed as onychorrhexis. Although impairment of life quality has not been evaluated for patients with brittle nail syndrome, the reduction of life quality in other nail problems has been studied and is evident. A proposed scoring system of key features of brittle nails is presented, and therapeutic approaches focussed on the pathogenic factors are discussed.

In vitro transungual permeation of ciclopirox from a hydroxypropyl chitosan-based, water-soluble nail lacquer

Commercial antimycotic nail lacquers are commonly based on water-insoluble resins. The present study was aimed at evaluating a novel, experimental nail lacquer (P-3051, Polichem SA, Lugano, Switzerland) based on the water-soluble film-forming agent hydroxypropyl chitosan (HPCH). The in vitro permeation of ciclopirox (CPX) from P-3051 and from a commercial, water-insoluble lacquer based on a vinyl resin (Penlac, Aventis Pharma), was investigated using thin membranes obtained from bovine hooves, an accepted model for human nails. Similar CPX permeation fluxes at steady state through the membranes, but significantly different lag times were observed for P-3051 and Penlac, when these were tested as dry films. The formulations thus appeared to influence only the time required by CPX to saturate the membrane, and not the final drug concentration gradient in the membrane. Permeation experiments performed on the same membranes and on hairless mouse skin with P-3051 and with a similar, HPCH-free vehicle (ERV), both tested in liquid form, disproved the possibility that HPCH might act as a permeation enhancer for CPX in either substrate. The possible reasons for the greater efficiency of the HPCH vehicle in terms of CPX transfer from the vehicle itself to the keratin membrane are discussed. This effect might be tentatively attributed to a particular affinity of HPCH for the membrane, resulting in intimate contact and strong adhesion of the HPCH lacquer to the keratin substrate.

Topical antifungal drugs for the treatment of onychomycosis: an overview of current strategies for monotherapy and combination therapy

BACKGROUND

Onychomycosis is a relatively common disease accounting for up to 50% of all nail disorders and its prevalence rises with age. As onychomycosis is an important medical disorder affecting both patient's health and quality of life, it requires prompt and effective treatment.

OBJECTIVE

Topical antifungal nail lacquers have been formulated to provide efficient delivery to the nail unit. As both amorolfine and ciclopirox have proved useful as monotherapy for onychomycosis that does not involve the nail matrix area, the purpose of this article is to check if, when combined with oral agents, the effectiveness and scope of treatment can be improved further.

METHODS

Combining data for mycological cure with clinical success (nail morphology) provides a more exacting efficacy measure.

RESULTS

Clinical investigations have shown that the combination of oral therapies with antifungal nail lacquer can confer considerable advantage over monotherapy with either drug type.

CONCLUSION

The improved effectiveness and economic advantages of combined topical/oral therapies benefit both patients and health providers; these treatment regimens therefore have an important role to play in the modern management of onychomycosis.

The oral antifungal patient

With the launch of the modern generation of oral antifungals almost a decade ago, an infection that was once thought of as intractable can now be cured. These drugs all offer the advantages of high efficacy rates, short-course therapy, and relative safety. However, they are far from perfect and not indicated in every situation. This article discusses issues such as patient selection, management, monitoring, and long-term follow-up.

Management of onychomycosis with topicals

Of all superficial fungal infections, onychomycosis is the most difficult to manage. Practitioners of all disciplines realize its chronic nature, difficulty in eradication, and propensity to recur. Topical treatment of onychomycosis, as opposed to oral therapies, offers a distinct advantage by allowing the patient to apply medication directly to the affected area, thus decreasing the potential for serious adverse events, such as drug toxicity and drug interactions. In the past, a multitude of topical antifungal agents were used in the treatment of onychomycosis; however, an acceptable level of scientific evidence regarding their effectiveness was lacking and this was evident by poor success rates. The development of a comparatively effective topical agent, the only one so far to gain FDA approval, has renewed interest in this form of therapy. Improved versions are being developed that may overcome the shortcomings of the first approved topical agent.

Onychomycosis in Denmark: prevalence of fungal nail infection in general practice

The study was initiated in order to get knowledge of the frequency of onychomycosis in patients visiting general practitioners in Denmark. A study design was using a display showing photos of abnormal nails including fungal infection, a clinical examination and a questionnaire. The practitioners obtained nail material. Direct microscopy and culture as well as histopathology, were carried out blindly in two different mycological laboratories. A number of 8546 patients were seen during the 6 months of the study, 5755 (67.3%) took part in the investigation. Clinical abnormal nails were observed in 948 (16.5%) patients, 52% males and 48% females, aged 18-92, mean 55 years old. Onychomycosis caused by dermatophytes were found in 238 (4.1%) and by Candida albicans in 45 (0.8%). Trichosporon cutaneum and Scopulariopsis brevicaulis were isolated each in 15 cases as single cultures. Onychomycosis, was typically seen in toenails as the distal-lateral type in males more than 40 years old. Predisposing factors were familiar dermatophytosis (22%), trauma (16.9%), diabetes mellitus (6.7%) and peripheral circulatory insufficiency (5.9%).

Itraconazole pulse therapy improves the quality of life of patients with toenail onychomycosis

BACKGROUND

Toenail onychomycosis is a common disease that can have serious adverse effects on the quality of life (QOL) of patients.

AIM

To evaluate the impact of itraconazole pulse therapy on the QOL of patients with toenail onychomycosis.

METHODS

A total of 20 patients with disto-lateral subungual toenail onychomycosis were treated with itraconazole 200 mg twice daily for 1 week every 4 weeks for 12 weeks. The patients were asked to complete a QOL questionnaire before treatment and on the last follow-up visit (week 48). A score of 0-4 was given according to the five possible responses to each question and these were summed to give the final score of the patient. The mean of the final scores of the patients before and after treatment were compared using the Wilcoxon matched-pairs test.

RESULTS

At 48 weeks after commencing treatment, 14 patients (70%) responded to treatment (nine patients were cured with almost totally clear toenails and five patients improved), and 16 patients (80%) were mycologically cured (negative KOH smear and culture). The mean of the QOL scores of the patients before treatment was 18.0+/-7.8, which reduced to 13.1+/-11.3 after treatment (two-tailed, p=0.009).

CONCLUSION

Itraconazole pulse therapy is an effective treatment and can improve the QOL of patients with toenail onychomycosis.

Dermatophyte test medium culture for evaluating toenail infections in patients with diabetes

OBJECTIVE

To evaluate the performance of the in-office dermatophyte test medium (DTM) culture when used to confirm the diagnosis of onychomycosis in diabetic patients.

RESEARCH DESIGN AND METHODS

Nail samples from 184 diabetic patients who exhibited symptoms consistent with toenail onychomycosis were screened for dermatophyte fungal infection using DTM, potassium hydroxide evaluation, and central mycology laboratory culture tests. The diabetic patient group investigated in this study is a subset of a heterogeneous set of patients who participated in a nationwide survey designed to investigate the use of fungal culture tests by dermatologists, podiatrists, and primary care physicians described in detail elsewhere. The overall sensitivity of the DTM and central laboratory culture methods was estimated and compared. Sensitivity differences between DTM and central laboratory culture methods were tested for statistical significance using the McNemar statistic.

RESULTS

DTM culture was positive in 102 of 184 patients (55%), while the central laboratory culture test detected the existence of fungal infection in 78 of 184 (42%). The two tests were in agreement (both positive or both negative) in 114 of 184 patients (62%). Central laboratory culture identified dermatophytes as the pathogen in 91% of positive cases.

CONCLUSIONS

DTM is a convenient and inexpensive culture test that can be used to confirm dermatophyte infections in diabetic patients with presumed onychomycosis. We found this test to be well suited for use in the primary care setting. Because oral antifungal agents are effective against dermatophyte species, which cause the vast majority of nail infections, diagnosis of onychomycosis requires confirmation of dermatophyte infection only, not identification of genus and species. DTM fulfills this requirement and has a diagnostic yield comparable to central laboratory culture.

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.

Fungal nail infections: far more than an aesthetic problem

Onychomycosis (fungal nail infection) is common and causes considerable discomfort and pain for many otherwise health patients. However, onychomycosis is especially prevalent in some patient groups seen regularly by community nurses (e.g. the elderly and people with diabetes, human immunodeficiency virus (HIV) infection or psoriasis). This article discusses the causes and types of onychomycosis, and examines in detail the various treatments available. Both the infection and its treatment can cause several clinical problems including drug interactions, difficulties with differential diagnosis and compromise of clinical outcomes. In particular, onychomycosis can undermine foot care in people with diabetes. The role of community nurses in treating and preventing onychomycosis is discussed.

Tinea pedis in European marathon runners

BACKGROUND

Epidemiological studies suggest that 15% of the population in industrial countries suffer from tinea pedis (athlete's foot) and that persons who do sports are a high-risk population.

OBJECTIVE

To investigate the responsibility of dermatophytes in interdigital lesions of the feet in European marathon runners and to identify associated risk factors.

SUBJECTS AND METHODS

Runners of the 14th Médoc Marathon (n = 147) were interviewed on risk factors for tinea pedis and underwent physical and mycological examinations.

RESULTS

Interdigital lesions of the feet were found in 66 runners (45%). A dermatophyte was isolated in 45 runners (31%), 12 of whom were asymptomatic. Trichophyton interdigitale and T. rubrum accounted for 49% and 35.5%, respectively, of the cases of tinea pedis. Thirty-three (22%) of the 102 runners free of dermatophyte infection had lesions resembling those of tinea pedis. Increasing age and use of communal bathing facilities were predictive of T. rubrum culture.

CONCLUSIONS

Marathon runners are at high risk for tinea pedis, but dermatophytes are responsible for only half of the foot lesions found in runners. The existence of asymptomatic carriers calls for prophylactic measures.

A psychometric study of patients with nail dystrophies

BACKGROUND

Survey studies suggest that patients with various dermatologic conditions experience concomitant psychologic distress.

OBJECTIVE

The purpose of this study was to determine which types of psychologic distress may be correlated with dystrophic disease of the nail in nonpsychiatric patients.

METHODS

Fifty-seven adult subjects presenting for treatment of nail dystrophies completed a survey instrument, which included 5 psychometric measures.

RESULTS

On average, patients rated the severity of their nail dystrophy and functional deficit higher (7.40/10 and 6.00, respectively) than investigators (6.15 and 3.75, respectively). Compared with age- and sex-matched nonpsychiatric patients, subjects in the study were moderately more anxious and minimally to mildly more depressed. Subjects had moderately depressed total self-concept, but their body image was approximately normal. Overall, subjects exhibited markedly more severe psychologic symptoms (84th percentile) than the normal sample, with the scores on the psychoticism, obsessive-compulsive, and paranoid ideation subscales being the most elevated.

CONCLUSION

The subjects with nail dystrophy had markedly exacerbated psychologic symptoms compared with age- and sex-matched nonpsychiatric patients.

An overview of fungal infections

The incidence of fungal infections is increasing at an alarming rate, presenting an enormous challenge to healthcare professionals. This increase is directly related to the growing population of immunocompromised individuals, resulting from changes in medical practice such as the use of intensive chemotherapy and immunosuppressive drugs. HIV and other diseases which cause immunosuppression have also contributed to this problem. Superficial and subcutaneous fungal infections affect the skin, keratinous tissues and mucous membranes. Included in this class are some of the most frequently occurring skin diseases, affecting millions of people worldwide. Although rarely life threatening, they can have debilitating effects on a person's quality of life and may in some circumstances spread to other individuals or become invasive. Most superficial and subcutaneous fungal infections are easily diagnosed and readily amenable to treatment. Systemic fungal infections may be caused by either an opportunistic organism that infects an at-risk host, or may be associated with a more invasive organism that is endemic to a specific geographical area. Systemic infections can be life threatening and are associated with high morbidity and mortality. Because diagnosis is difficult and the causative agent is often confirmed only at autopsy, the exact incidence of systemic infections is difficult to determine. The most frequently encountered pathogens are Candida albicans and Aspergillus spp. but other fungi such as non-albicans Candida spp. are increasingly important.

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.

Measuring the impact of onychomycosis on patient quality of life

According to survey research, onychomycosis, a fungal infection of the toenail or fingernail, affects quality of life including physical and social functioning and emotional health. We developed an onychomycosis disease-specific questionnaire (ODSQ) that sensitively assessed symptom distress, functional impact, and social stigma associated with the disease. Samples of patients enrolled in a randomized controlled clinical trial were used for the psychometric evaluations. The multi-item scales were internally consistent (alpha > or = 0.80) and reproducible (ICC > 0.85). Interscale correlations between the ODSQ and generic scales were moderate and consistent with the hypothesized magnitude and directions. Construct validation, employing known groups analysis, supported the hypothesized impact of onychomycosis on three domains of quality of life: physical functioning, emotional health, and social functioning. Significant differences were found between clinically "cured", "improved", or "failed" patients, and between mycologically "eradicated" and "persistent" patients. The ODSQ was responsive to clinical change and more sensitive than derived Medical Outcomes Study Short Form-36 scales. The ODSQ provides reliable, validated and responsive information about the consequences of onychomycosis and its treatment.

Onychomycosis. Treatment, quality of life, and economic issues

Onychomycosis is a public health concern because of its high worldwide incidence and prevalence, and its potential for spread of fungal elements to others, as well as complications such as cellulitis, bacterial infection, pain, and extensive dermatophytic infections. The incidence of onychomycosis has been increasing, particularly in individuals over 60 years of age, patients with HIV infection, and patients with diabetes mellitus. Onychomycosis may impact upon physical, functional, psychosocial, and emotional aspects of life. Difficulty walking, wearing shoes, and embarrassment are common complaints. Quantification of such quality-of-life changes are significant to clinical practice in that many factors can affect overall patient health. In light of the potential clinical implications on physical and mental health, onychomycosis should be considered a medical condition that deserves rigorous clinical management. Onychomycosis can be treated effectively and with comparative safety with the new generation of oral antifungal agents (itraconazole, fluconazole and terbinafine). Significantly improved pharmacokinetic and pharmacodynamic profiles permit markedly reduced duration of administration, individual drug exposure, and ultimately enhanced patient compliance and satisfaction with therapy. In addition, a number of pharmacoeconomic studies have documented the cost effectiveness of these newer agents compared with both traditional pharmacologic treatment and topical therapies. The currency figures quoted are 1997 values. With regard to continuous oral antifungal regimens, terbinafine therapy has been found to be most cost effective in the treatment of toenail onychomycosis, with a drug acquisition cost of $US522.50. However, improved safety, tolerability, efficacy and cost effectiveness have been documented with itraconazole intermittent, pulse regimens. With itraconazole pulse therapy, the drug acquisition cost decreases to $US488.90. Additionally, the total cost of medical management is less for itraconazole therapy compared with that of terbinafine ($US261.00 vs $US306.00). Because sensitivity analyses for itraconazole and terbinafine have been found to be somewhat comparable in terms of mycological cure, clinical response, and relapse rates, other variables such as safety and efficacy profiles, and patient attitudes and expectations toward therapy need to be considered when formulating an onychomycosis pharmacologic treatment plan. The drug aquisition cost of fluconazole given as a 300 mg dose once weekly for 6 months is $US562.76 and given as a 150 mg dose once weekly (for 6 months) $US281.38.

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.

Onychomycosis: therapeutic update

Onychomycosis is a common disease of the nail unit caused by dermatophytes, yeasts, and molds. In more than 80% of cases, onychomycosis is caused by the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes. The prevalence of onychomycosis in the world's population is 2% to 18% or higher and accounts for approximately 50% of all nail disorders. Until recently, available therapies were inadequate because of low cure rates, high relapse rates, and often dangerous side effects. An increased understanding of nail pharmacokinetics has led to the development of safer, more effective systemic therapies for onychomycosis, such as itraconazole, fluconazole, and terbinafine. These new oral antifungal agents allow shorter periods of treatment, provide rapid efficacy, and may improve patient compliance and attitudes regarding therapy. Treatment selection will depend on several factors, including appropriate spectrum of activity, adverse effects, and potential drug interactions plus patient preferences for specific dosing regimens.