Search Results
Background:
Onychomycosis is a chronic nail infection caused by dermatophytes, Candida, nondermatophyte molds, and Trichosporon. The purpose of this study was to identify the underlying pathogen in patients with onychomycosis in our region.
Methods:
A retrospective analysis of 225 cases with onychomycosis, diagnosed over a 27-month period at the Department of Dermatoveneorology, Bezmialem Vakif University, Istanbul, Turkey, and confirmed with culture, was performed.
Results:
Patient age ranged from 2 to 87 years (mean ± SD, 41.59 ± 17.61), and female patients were more commonly affected (120 cases, 53.3%) than male patients. Lateral and distal subungual onychomycosis was detected in 180 cases (80%). Etiologic agents were as follows: Trichophyton rubrum, 77 cases (34.2%); Trichophyton mentagrophytes, 30 cases (13.3%), Candida albicans, 28 cases (12.4%); Candida parapsilosis, 25 cases (11.1%); Acremonium species, one case (0.4%); Aspergillus species, two cases (0.9%); Fusarium species, four cases (1.3%); and Trichosporon species, three cases (1.3%).
Conclusions:
The most frequent isolated etiologic agents were T rubrum for toenails and C albicans for fingernails.
Although scanning electron microscope technology has been used for more than 60 years in many fields of medical research, no studies have focused on obtaining high-resolution microscopic images of onychomycosis of the toenail caused by Trichophyton rubrum in a geriatric population. To provide new insight into the intricate structure and behavior of chronic toenail onychomycosis, we produced three-dimensional images of onychomycosis obtained from two geriatric patients with confirmed growth of T rubrum. The photomicrographs illustrate the pervasive integration and penetration of the fungus hyphal elements, underscoring the clinical difficulty of obtaining rapid treatment of fungal infections in the distal and lateral subungual space of the human toenail. Although the scanning electron microscope may not be a practical diagnostic tool for most physicians, it remains invaluable for the researcher to obtain insight into the spatial orientation, behavior, and appearance of onychomycosis. (J Am Podiatr Med Assoc 94(4): 356–362, 2004)
Efficacy of Terbinafine for Toenail Onychomycosis
A Multicenter Trial of Various Treatment Durations
The efficacy of terbinafine (250 mg/day) in the treatment of toenail onychomycosis was evaluated in a large open-label, multicenter trial of 12, 18, and 24 weeks of therapy. All 1,534 patients had onychomycosis, confirmed by either positive potassium hydroxide (KOH) wet mount, positive fungal culture, or both, and all received at least 12 weeks of treatment. Treatment was continued for an additional 6 or 12 weeks, depending on the extent of the disease at follow-up. Mycologic cure rates (negative culture plus negative KOH) at week 72 were 72.1% in the 12-week treatment group, 72.5% in the 18-week group, and 77.0% in the 24-week group. In all groups, clinical cure rates were higher at week 72 than at week 48: 49.5% of the 12-week group, 49.2% of the 18-week group, and 44.6% of the 24-week group experienced clinical cure by the end of the study. Both mycologic and clinical recurrence rates were low in all treatment groups at the 72-week assessment. The results of this study confirm the efficacy of terbinafine in the treatment of toenail onychomycosis as demonstrated in previous registration and large-scale clinical trials. (J Am Podiatr Med Assoc 91(3): 127-131, 2001)
Onychomycosis is a common problem seen in clinical practice. Given the differential diagnosis of dystrophic nails, it is helpful to obtain a definitive diagnosis of dermatophyte infection before initiation of antifungal therapy. Potassium hydroxide preparation and fungal culture, which are typically used in the diagnosis of these infections, often yield false-negative results. Recent studies have suggested that nail plate biopsy with periodic acid–Schiff stain may be a very sensitive technique for the diagnosis of onychomycosis. In this article, we review the literature on the utility of histopathologic analysis in the evaluation of onychomycosis. Many of these studies indicate that biopsy with periodic acid–Schiff is the most sensitive method for diagnosing onychomycosis. We propose that histopathologic examination is indicated if the results of other methods are negative and clinical suspicion is high; therefore, it is a useful complementary technique in the diagnosis of onychomycosis. (J Am Podiatr Med Assoc 95(3): 258–263, 2005)
Treatment of Dermatophyte Toenail Onychomycosis in the United States
A Pharmacoeconomic Analysis
This study attempted to determine the cost-effectiveness of therapies for dermatophyte toenail onychomycosis in the United States in 2001. The antimycotic agents evaluated were ciclopirox 8% nail lacquer and the oral agents terbinafine, itraconazole (pulse), itraconazole (continuous), fluconazole, and griseofulvin. A treatment algorithm for the management of onychomycosis was developed, and a meta-analysis was carried out to determine the average mycologic and clinical response rates for the various agents. The cost of the regimen was figured as the sum of the costs of drug acquisition, medical management, and management of adverse effects. The expected cost of management and disease-free days were determined, and a sensitivity analysis was conducted. It was concluded that ciclopirox 8% nail lacquer, which has recently become available in the larger size of 6.6 mL, is a cost-effective agent for the management of toenail onychomycosis. (J Am Podiatr Med Assoc 92(5): 272-286, 2002)
Background: Onychomycosis is a chronic fungal nail infection caused predominantly by dermatophytes, and less commonly by nondermatophyte molds and Candida species. Onychomycosis treatment includes oral and topical antifungals, the efficacy of which is evaluated through randomized, double-blind, controlled trials for US Food and Drug Administration approval. The primary efficacy measure is complete cure (complete mycologic and clinical cure). The secondary measures are clinical cure (usually ≤10% involvement of target nail) and mycologic cure (negative microscopy and culture). Some lasers are US Food and Drug Administration approved for the mild temporary increase in clear nail; however, some practitioners attempt to use lasers to treat and cure onychomycosis.
Methods: A systematic review of the literature was performed in July of 2020 to evaluate the efficacy rates demonstrated by randomized controlled trials of laser monotherapy for dermatophyte onychomycosis of the great toenail.
Results: Randomized controlled trials assessing the efficacy of laser monotherapy for dermatophyte toenail onychomycosis are limited. Many studies measured cure rates by means of nails instead of patients, and performed only microscopy or culture, not both. Only one included study reported mycologic cure rate in patients as negative light microscopy and culture (0%). The combined clinical cure rates in short- and long-pulsed laser studies were 13.0%–16.7% and 25.9%, respectively. There was no study that reported the complete cure rate; however, one did report treatment success (mycologic cure [negative microscopy and culture] and ≤10% clinical involvement) in nails as 16.7%.
Conclusions: The effectiveness of lasers as a therapeutic intervention for dermatophyte toenail onychomycosis is limited based on complete, mycologic, and clinical cure rates. However, it may be possible to use different treatment parameters or lasers with a different wavelength to increase the efficacy. Lasers could be a potential management option for older patients and onychomycosis patients with coexisting conditions such as diabetes, liver, and/or kidney diseases for whom systemic antifungal agents are contraindicated or have failed.
Diagnosis and Prevalence of Onychomycosis in Diabetic Neuropathic Patients
An Observational Study
Background: An observational study was conducted to assess the prevalence of onychomycosis in clinically suspected diabetic neuropathic patients and to assess the reliability of the diagnosis.
Methods: One hundred successive type 1 and 2 diabetic patients with diabetic neuropathy were followed. Diabetic neuropathy was defined by a vibration perception threshold greater than 25 V and onychomycosis by clinical diagnosis. Samples of the most affected nail were taken. Potassium hydroxide testing and culture were performed. Photographs of the nails were used by two dermatologists for diagnosis.
Results: The mean ± SE age was 62.3 ± 11.4 years for the 20 onychomycotic patients and 60.3 ± 10.4 years for the entire cohort; 14 onychomycotic patients (70%) were male versus 56 in the full cohort (56%) (P < .05). The prevalence of onychomycosis was 20% (culture and potassium hydroxide test positive) and 24% (culture positive). Twenty or 30 patients were positive by the potassium hydroxide test, depending on the investigator. The most frequent pathogen found was Trichophyton rubrum (11 of 20 patients; 55%). The positive predictive values of the dermatologist’s diagnoses were 57.8% and 35.6%, and the negative predictive values were 85.0% and 90.5%. The two expert’s results were significantly different (P < .05).
Conclusions: The diagnosis of onychomycosis is difficult to make. The diagnostic methods commonly used are not satisfactory. If onychomycosis is dangerous for the diabetic foot, a better diagnostic method is needed. (J Am Podiatr Med Assoc 99(2): 135–139, 2009)
The Diagnosis of Onychomycosis in a Geriatric Population
A Study of 450 Cases in South Florida
An investigative study was performed to determine the diagnosis of onychomycosis in a South Florida geriatric population. In this study, 450 cases of suspected onychomycosis involving men and women 65 years of age and older from a private practice office and two nursing home settings were used. Samples were taken from the hallux toenail and sent to a mycology laboratory for fluorescent potassium hydroxide (KOH) preparation and microscopic examination of a fungal culture. Of the 450 cases studied, 46.4% of the patients had a single fungal organism cultured, 30.4% had a mixed fungal infection cultured, and 23.1% had no fungal growth. Saprophytes were found in 59.9% of the 526 total fungal organisms cultured while dermatophytes were found in only 23.8%. The results of this investigation demonstrate that there may be a shift from isolated dermatophyte infection to mixed saprophyte infections in a geriatric population with onychomycosis. (J Am Podiatr Med Assoc 91(9): 456-464, 2001)
Placebo cure rates vary among randomized clinical trials for onychomycosis, but the factors influencing these cure rates have not been systematically investigated. The PubMed database and reference sections of relevant publications were searched for randomized controlled trials of dermatophyte toenail onychomycosis that included a placebo control and that assessed cure rates. From 21 studies, the pooled mean ± SD placebo cure rates regarding mycological, clinical, and complete cure were 8.7% ± 3.7%, 3.4% ± 2.2%, and 1.2% ± 1.4%, respectively. There was no statistically significant difference between oral and topical treatments. None of the cure rates significantly correlated with any of the participant or study design characteristics analyzed. Placebo cure rates in randomized controlled trials of toenail onychomycosis are relatively low and are independent of the study characteristics.
The follow-up results of a 9-month observational study of 150 onychomycosis patients treated with a variety of mechanical, topical, and oral therapies by podiatric physicians and dermatologists are presented. Changes from baseline in toenail condition and patient satisfaction were assessed at 4- and 9-month follow-up. At 9 months, patients who had received oral therapy reported significantly fewer onychomycosis-related problems in social situations, including embarrassment or self-consciousness about the appearance of nails, avoidance of contact by others, being perceived as unclean or untidy, and the desire to keep their nails concealed. Patient-reported satisfaction with the treatment program was significantly higher for those receiving oral therapy than for those receiving nonoral therapy. (J Am Podiatr Med Assoc 91(10): 521-527, 2001)
