Common Fungal Infections of the Feet in Patients with Diabetes Mellitus

Superficial fungal infections of the foot (tinea pedis and onychomycosis) are common among elderly patients. Although most authorities believe that patients with diabetes mellitus have an increased predisposition to dermatophytic infections, some controversies still remain. Because these infections disrupt the skin integrity and provide an avenue for bacterial superinfection, elderly diabetic patients with dermatophytic infection should be promptly treated with an antifungal agent. For most dermatophytic infections of the foot, topical agents are usually effective and less expensive than oral agents. Laboratory diagnosis of fungal infection prior to institution of therapy is recommended. Proper technique for obtaining the specimen is important to ensure a higher chance of isolating the infecting fungus. Commonly used anti-dermatophytic agents that are also active against the yeasts include the imidazoles, the allylamines-benzylamines and the hydroxypyridones, which are also effective against most of the moulds. Oral therapy for tinea pedis, although not well studied, should be limited to patients with more extensive infections, such as vesicobullous and moccasin type, resistant infections or chronic infections. In addition, oral agents should also be considered in diabetic and immunosuppressed patients. On the other hand, treatment of onychomycosis of the foot usually requires systemic therapy. Griseofulvin is the least effective agent when compared with the newer agents. Terbinafine, itraconazole and fluconazole have been shown to have acceptable cure rates. More recently, topical treatment of the nail with 8% ciclopirox nail lacquer, bifonazole with urea and amorolfine have been reported to be successful. Over the past decade, fungal foot infections of the skin and nail are more effectively treated with the introduction of numerous topical and oral agents.

Interdigital tinea pedis (dermatophytosis simplex and complex) and treatment with ciclopirox 0.77% gel

The most common presentation of tinea pedis (athlete's foot) is that involving the interdigital spaces. Tinea pedis interdigitalis may present as asymptomatic dermatophytosis simplex or dermatophytosis complex, which is symptomatic, with secondary bacterial infection. In the dermatophytosis complex presentation there may be inflammation, maceration and odor, with bacterial involvement. Ciclopirox gel offers advantages in the treatment of tinea pedis, especially in the dermatophytosis complex presentation, with antifungal, antibacterial, and anti-inflammatory activity; furthermore, the gel formulation is fast drying, which is an advantage when the toe web area is moist.

Tinea corporis, tinea cruris, tinea nigra, and piedra

Tinea infections are among the most common dermatologic conditions throughout the world. To avoid a misdiagnosis, identification of dermatophyte infections requires both a fungal culture on Sabouraud's agar media, and a light microscopic mycologic examination from skin scrapings. Topical antifungals may be sufficient for treatment of tinea corporis and cruris and tinea nigra, and the shaving of hair infected by piedra may also be beneficial. Systemic therapy, however, may be required when the infected areas are large, macerated with a secondary infection, or in immunocompromised individuals. Preventative measures of tinea infections include practicing good personal hygiene; keeping the skin dry and cool at all times; and avoiding sharing towels, clothing, or hair accessories with infected individuals.

Treatments of tinea pedis

The severity of tinea pedis infection determines the course of treatment required. Mild infections may be resolved using a topical agent. More severe presentations (eg, dermatophytosis complex) may require treatment that eliminates the bacterial and fungal infection. Some topical monotherapies may exhibit both antifungal and antibacterial activity. In other instances, it may be necessary to combine an antifungal agent with an antibacterial agent. If inflammation is present, an agent with known anti-inflammatory action may need to be used. The chronic presentation of tinea pedis (dry type) sometimes does not respond well to topical therapy. In such instances, systemic antifungal therapy is required to ensure that adequate concentrations of the therapeutic agent are present at the site of infection.

[Epidemiology of mycoses in submariners based on the Kola Peninsula]

Subject of the study was spreading of mycoses in the troops based on the Kola Peninsula. Examined were the military serving on atomic submarines, maintenance crews of deactivated atomic submarines awaiting disposal, and coastal units. Spreading of skin lesions among the submariners was not same as among the coastal military. Signs of clinical mycoses were observed in 41.2% of submariners of the active unit, in 66.9% of the maintenance crews, and in 38.1% of the coastal military. Infection agents were fungi g. Candida (albicans, guilliermondii, krusei, pseudotropicalis), Epidermophytia plicarum, Ptyriasis versicolor, Trichophyton interdigitale. Among the fighters on active submarines, 53.8% of the clinical observations were accounted for onychomycosis and foot skin lesions and 38.5%--for erythema, maceration and suppuration. Among the maintenance crews 51.8% of the observations were accounted for onychomycosis and foot skin lesions and maceration; hyperkeratosis and fissures prevailed in the coastal military (31.1%). For submariners most common were Candida albicans (80.7%) and guilliermondii (11.6%), and Trichophyton interdigitale (7.7%). In the maintenance crew those were Candida albicans (84.1%) and guilliermondii (11.6%) and in the coastal military, Candida albicans (70.6%), guilliermondii (11.8%) and krusei (14.7%).

Inflammatory tinea pedis/manuum masquerading as bacterial cellulitis

BACKGROUND

Tinea pedis and tinea manuum in children are more common than previously recognized. Clinical presentations of dermatophyte infections may vary in children and may be difficult to diagnose.

OBJECTIVE

To show the necessity of potassium hydroxide preparations and/or fungal cultures in assessing suspicious cases of cellulitis in children who may have dermatophyte infections.

PATIENTS

We describe 4 children with inflammatory tinea pedis or tinea manuum who were initially misdiagnosed as having bacterial cellulitis.

INTERVENTION

A potassium hydroxide examination was performed on 3 patients. Fungal cultures were performed on 2 patients.

RESULTS

Inflammatory/bullous dermatophyte infections were detected by potassium hydroxide examination in all 4 patients and all 4 children successfully responded to topical antifungal therapy.

CONCLUSIONS

These cases demonstrate that inflammatory tinnea pedis/manuum can masquerade as cellulitis in children. Early potassium hydroxide examination can allow appropriate antifungal treatment to be initiated before fungal culture results are finalized.

["Banal dermatomycoses" that cannot be overlooked]

Two young adults presented an interdigital intertrigo and a dyschromic nail alteration, respectively. They were adept of intense sport swimming in pools. Lesions had been misdiagnosed as athlete's foot and onychomycosis, respectively. Several antifungal treatments had been tried without success. After many months of inadequate management, the dermatological examination revealed the presence of two malignant melanomas corresponding to the eroded acrolentiginous and nodular subungueal types, respectively.

AFSS: athlete's foot severity score. A proposal and validation

We developed a simple scoring system to evaluate the severity of tinea pedis (Athlete's foot severity score, AFSS). The AFSS consists of a clinical evaluation, using a three-point scale, of erythema and scaling in the plantar and interdigital spaces of the feet, and counts of interdigital spaces involved. Each foot is evaluated separately. The validity of the AFSS was assessed in 224 soldiers of the Israel Defense Force using mycological cultures as the main outcome measure and subjective assessment of pruritus as the secondary outcome measure. Mycological examinations were performed in 106 patients who had clinical evidence of tinea pedis. AFSS was significantly associated with culture results (P<0.0001), as well as with the presence of pruritus (P=0.002), and pruritus scores (P=0.025). We conclude the AFSS is valid for the clinical evaluation of tinea pedis severity in military settings. The application of AFSS to civilian morbidity should be subjected to further evaluation. AFSS: Schweregrad-Beurteilung des Athletenfusses. Ein Vorschlag

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.

Cutaneous fungal infections in the elderly

Fungal infections are common in all age groups, including the elderly. In the elderly patient, unique challenges may exist in the diagnosis and treatment of these diseases. However, proper therapy for these prevalent conditions leads to a better quality of life.

Dermoscopy in the diagnosis of tinea nigra plantaris

Tinea nigra is a relatively uncommon dermatiaceous fungal infection, usually caused by Phaeoannellomyces werneckii, that may mimic a melanocytic lesion. We describe the value of epiluminescent dermoscopy of tinea nigra plantaris compared with other common diagnostic tools and procedures available (clinical appearance, potassium hydroxide [KOH], culture, culture mount preparation, and biopsy). A case of tinea nigra plantaris was evaluated clinically, microscopically with KOH, and dermatoscopically. Dermatoscopic findings were evaluated according to the Stolz system. Dermoscopy, clinical presentation, and microscopy with KOH all confirmed the diagnosis, with dermoscopy being the fastest and simplest procedure. Dermoscopy is a useful clinical adjuntive tool in differentiating tinea nigra from a melanocytic lesion.

A better potassium hydroxide preparation? In vivo diagnosis of tinea with confocal microscopy

BACKGROUND

Traditional diagnostic testing for dermatophyte infection currently requires skin scraping for light microscopy and/or fungal culture or skin biopsy. Immunofluorescent microscopy can also be used with calcofluor stain. All of these tests can be time-consuming to perform, require a waiting period for results, and are invasive. We investigated the use of a real-time, noninvasive, confocal microscope in visualizing dermatophyte hyphae in vivo.

OBSERVATIONS

Confocal microscopic imaging of active tinea can clearly identify dermatophyte hyphae within the upper epidermis after potassium hydroxide application. The hyphae appear as bright linear branching objects not found in uninvolved skin.

CONCLUSIONS

It is possible to immediately and painlessly image dermatophyte hyphae in active lesions of tinea by means of a confocal microscope. With further improvement, imaging devices may be available to physicians to instantly and noninvasively evaluate a variety of skin disorders in microscopic detail.

[New developments in medical mycology]

Not only have the systemic mycoses clearly increased in number but also mycoses of the skin are more common than presumed in the past. Today onychomycosis is found in up to 10% of human beings. Onychomycosis can compromise quality of life markedly. Common tinea pedis is one of the most important risk factors for erysipelas of the lower legs. The clinical presentation of oral candidosis in HIV-infected patients is changing; Candida dubliniensis has been identified as another important causative microorganism. Onychomycosis today in most cases can be cured using terbinafine or itraconazole. When choosing the ideal drug in a given case, both the benefit risk ratio and the benefit cost ratio have to be taken into account. Liposomally encapsulated amphotericin B represents a major breakthrough in the treatment of systemic mycoses or fever of unknown origin. The same applies to liposomally encapsulated econazole with respect to tinea pedis. In regard to the pathogenesis of Candida infections the family of secreted aspartic proteinases plays a major role as a virulence factor and possible future target for antimycotic treatment.

Recognizing, treating, and preventing common foot problems

The incidence, prevalence, and severity of foot conditions increase with age. Teaching patients simple preventive techniques is crucial. Recognition, treatment, and prevention of common foot complaints--i.e., toenail problems, infections, corns and calluses, injuries, flat feet, bunions, arthritis of the toes, and toe and joint deformities--are reviewed.

Pustular tinea pedis

Pustules are uncommon in tinea pedis and may suggest a bacterial infection. We describe a patient with large pustules on his feet that contained hyphae on Gram's stain of the pus and on a potassium hydroxide preparation of the pustule roof. Cultures were negative for bacteria, but grew Trichophyton rubrum.

Bilateral tinea nigra plantaris and tinea nigra plantaris mimicking melanoma

Tinea nigra, a superficial fungal infection caused by Phaeoannellomyces werneckii, presents as a hyperpigmented, nonscaling macule of variable size and shape. Typically lacking induration, erythema, or pruritus, these "ink spot" lesions may resemble junctional nevi or malignant melanoma. Rapid, noninvasive diagnosis can be provided by potassium hydroxide examination, demonstrating numerous large, dematiaceous hyphae.

Achilles foot screening project: preliminary results of patients screened by dermatologists

OBJECTIVE

Presentation of the preliminary results from the foot screening project, 'Achilles', conducted in spring of 1997 and 1998 in several European countries. At the EADV congress, only the preliminary results of the study, i.e. patients screened by dermatologists, were presented.

SUBJECT

Foot diseases, especially fungal infections (tinea pedis and onychomycosis).

METHODS

A questionnaire and a mycological examination in patients visiting a dermatologist for disorders irrespective of their foot problems.

RESULTS

The proportion of patients with foot diseases visiting a dermatologist was high (58%). In the total population, fungal infections were the most prevalent clinically diagnosed foot diseases (35%), especially onychomycosis (23%) and tinea pedis (22%). The prevalence of foot diseases increased with advancing age and more men as compared with women had fungal infections of the feet. The most prevalent predisposing factors were vascular disease and sports participation. In subjects with onychomycosis, the big toenail was affected most often. Twenty-three percent of the participants with clinically diagnosed tinea pedis and/or onychomycosis had infection of both the skin and the nail. The most frequently isolated pathogen was Trichophyton rubrum. Patients with onychomycosis often reported quality of life problems, especially pain and discomfort in walking.

CONCLUSION

The preliminary results of this pan-European study show that epidemiological studies can give a better idea of foot diseases in dermatological patients. The results indicate a need to pay more attention to foot disease, to predict and prevent future diseases and complications. The most frequent foot diseases were fungal infections, especially onychomycosis, which affects the quality of life of the patients. More results will be available in 1999.

Achilles foot-screening project: background, objectives and design

OBJECTIVE

A description of the background, objectives and design of the Achilles foot screening project.

SUBJECT

Foot diseases, especially tinea pedis and onychomycosis.

METHODS

Literature review and description of the Achilles set-up.

RESULTS

The prevalence of tinea pedis and onychomycosis has sharply increased since 1950. Tinea pedis is one of the most common mycological diseases and onychomycosis is the most frequent nail disorder. They occur mainly in adults with an estimated overall prevalence of 10-20%, although epidemiological data are limited. The pan-European Achilles foot-screening project was undertaken to gather basic information on foot diseases, using a survey by questionnaire and a mycological assessment study.

CONCLUSION

The prevalence of foot mycoses, particularly onychomycoses, is much higher than anticipated.

Tinea pedis in children presenting as unilateral inflammatory lesions of the sole

Tinea pedis is uncommon in prepubescent children and therefore the diagnosis may be difficult to make. We report tinea pedis in five children presenting as unilateral inflammatory lesions of the sole which was not readily diagnosed. The pathogen in all of our cases was Trichophyton rubrum.

Common pediatric foot dermatoses

The pediatric foot dermatoses known as tinea pedis, shoe dermatitis, and juvenile plantar dermatosis are seen commonly in clinical practice. A knowledge of the clinical presentations and causes of these disorders can help pediatric and family nurse practitioners identify, diagnose, and treat childhood rashes of the feet. The conventional view in pediatrics is that small children rarely have tinea pedis. However, a 1992 study disputes this claim. Any child who has an atypical or persistent foot rash will need a referral or consultation.

Advances in the treatment of superficial fungal infections: focus on onychomycosis and dry tinea pedis

Onychomycosis is one of the most stubborn superficial mycoses. With few exceptions, oral antifungal therapy is needed to achieve resolution. Before oral itraconazole, fluconazole, and terbinafine hydrochloride became available, physicians had to rely on prolonged therapy with griseofulvin or oral ketoconazole. Of the newer oral agents, itraconazole appears to have the broadest spectrum of action, with therapeutic activity against dermatophytes, yeasts, and some nondermatophyte molds. Tissue pharmacokinetics accounts for significantly greater efficacy and much shorter treatment courses for fungal infections of the skin and nails. In general, oral itraconazole, fluconazole, and terbinafine are very well tolerated. The newer oral agents offer improved efficacy over griseofulvin and ketoconazole for onychomycosis and dry tinea pedis.

Allergic contact dermatitis from pyoctanin

Although pyoctanin is widely used in medicine, there are hardly any reports of contact allergy to it. Most reports of side-effects refer to irritant reactions after topical application. We describe 2 patients who developed pyoctanin contact dermatitis after long-term application on damaged skin. Positive patch test results down to concentrations of 0.0025% and 0.05% aqueous pyoctanin solution, respectively, were found.

Tinea pedis: clinical experience and efficacy of short treatment

Tinea pedis is the commonest fungal infection in developed countries. Topical therapy is an accepted and successful method for the management of this condition. This has usually involved the application of an antifungal twice or 3 times a day for 3-4 weeks to achieve a cure rate of > or = 80%. Terbinafine, a new antifungal, has been shown in a number of studies to give equally good results when applied once or twice daily for 1-2 weeks. In one study, a cure rate of 78% was achieved in patients with tinea pedis after a single application of 1% terbinafine cream, demonstrating the high potency of this antifungal. Topical terbinafine has also been compared to clotrimazole for the treatment of tinea pedis. Terbinafine 1% cream applied twice daily for 1 week was significantly superior to a 4-week course of clotrimazole 1% cream for treating this common mycosis. Overall, the high efficacy of topical terbinafine in treating tinea pedis following such-short-duration therapy is undoubtedly due to its fungicidal mode of action.

The descriptive epidemiology of tinea pedis in the community

Tinea pedis is a common inflammatory skin condition due to infection by dermatophyte fungi. A number of epidemiological studies have been completed on the frequency of tinea pedis in the community, particularly sporting and occupational groups and schools. Most studies have focused on small, high-risk populations. These include occupational groups involving manual labour, sporting groups such as swimmers, and those working or living in confined conditions with shared washing facilities, which favour the opportunity for cross-infection. Most studies show that the frequency of tinea pedis is higher in males than females. Tinea pedis infections appear to be least common among children, but do occur, and are commonly misdiagnosed. The difference between clinical disease and confirmed diagnosis by culture is not always clear when statistics of disease frequency have been presented. Clear diagnosis criteria indicating the level of mycologically confirmed diagnosis should be reported in future studies that include statistics on disease frequency. Future epidemiological studies should also aim to be population-based in order to obtain a more complete picture of disease frequency.

Diagnosing and treating onychomycosis

Onychomycosis is a persistent fungal infection of the toenails or fingernails that is usually not painful but is unsightly and can affect a patient's quality of life by interfering with footwear. It may affect up to 30% of the population by age 60. In more that 99% of cases, it is caused by dermatophytes, the most common of which are Trichophyton rubrum and Trichophyton mentagrophytes. Each of the four clinical types of onychomycosis, as defined by the route of fungal invasion, has a characteristic appearance, but other diseases, particularly psoriasis, may have a similar appearance. Proper management, therefore, includes confirmation of fungal infection by potassium hydroxide slide preparation and culture. Traditionally, pharmacologic treatment has been less than optimal. In many cases, griseofulvin, the first oral agent approved for onychomycosis in the United States, must be given for 1 year or more to be effective. Low cure rates are related to poor bioavailability and the fungistatic rather than fungicidal effect of the drug. Newer agents, such as oral itraconazole and oral terbinafine, promise to substantially increase cure rates while shortening treatment duration. Oral terbinafine is potently fungicidal against dermatophytes and has proven efficacious with regimens as brief as 12 weeks when the nail is not 100% involved.

Dermatophytosis of the feet

Tinea pedis is the most common fungal infection worldwide. There are three well-accepted clinical presentations based on the offending organism. Predisposing factors include heat, humidity, and occlusion. Mild disease can evolve to "dermatophytosis complex" through bacterial superinfection. Potassium hydroxide preparation and culture are important diagnostic tests in each case.

Tinea pedis: diagnosis and treatment

The authors review the common dermatophyte genera and the forms of tinea pedia they cause. They also provide a differential diagnosis, review diagnostic procedures, and outline the pathophysiology of this complex condition. A classification and treatment plan is provided, with an extensive review of recent clinical trials. The aim of the article is to expand practitioners' treatment options for individualizing treatment plans.

Minipreparation of total cellular DNA is useful as an alternative molecular marker of mitochondrial DNA for the identification of Trichophyton mentagrophytes and T. rubrum

Total cellular DNA was extracted from 18 isolates of Trichophyton mentagrophytes and six isolates of unidentified Trichophyton species taken from tinea corporis, tinea cruris and tinea pedis patients by a minipreparation method. The DNA was digested with the restriction enzymes HaeIII and MspI, followed by electrophoresis on agarose gels. The restriction enzyme profiles of the DNAs were compared with those of mitochondrial (mt) DNA extracted from reference strains of T. mentagrophytes (Arthroderma simii, A. benhamiae and A. vanbreuseghemii) and T. rubrum. All 18 T. mentagrophytes isolates showed the same DNA profiles as mtDNA from A. vanbreuseghemii. The six unidentified Trichophyton isolates exhibited DNA profiles the same as that of mtDNA from T. rubrum. Consequently, these isolates were identified as T. rubrum. In conclusion, restriction enzyme analysis of total cellular DNA prepared by the minipreparation method is considered to be useful as an alternative method of mtDNA analysis and is helpful for the identification of these dermatophyte species.

Tinea pedis survey in members of the Japanese Self-Defense Forces undergoing ranger training

The conditions surrounding tinea pedis infection were surveyed--the degrees of infection and of aggravation attendant upon training, and the skin temperature within the leather boots of members of the Japanese Self-Defense Forces undergoing winter and summer ranger training. Before winter training, tinea pedis was diagnosed in 8 of the 15 subjects. The mean atmospheric temperature was 7.1 degrees C, the total precipitation, 23 mm, and the mean skin temperature of the feet during training, 33.7 degrees C. After training, 1 further subject had contracted tinea pedis, 5 of the 8 showed slight aggravation, and 3 showed no change. Before summer training, tinea pedis was found in 9 of another 15 subjects. The mean atmospheric temperature was 20.0 degrees C, total rainfall, 353 mm, and the mean skin temperature of the feet during training, 36.6 degrees C. After the training, aggravation had occurred in 3 of the 9, and slight aggravation in the other 6. In these 9, vesiculation, pustules and erosion were seen, so that summer training had a more severe effect than winter training. Investigation of the predisposing factors for tinea pedis due to the wearing of boots and shoes is considered extremely important for the prevention and treatment of this disease.

Dermatologic disorders of the foot

This article includes a description of common problems of greatest interest to nondermatologist physicians who treat the foot. These include plantar warts, corns and callouses, toenail problems, and some common skin disorders, such as tinea pedis, pitted keratolysis, hyperkeratosis and fissures, and contact dermatitis. Certain neoplasms, including squamous cell carcinoma, verrucous carcinoma, and melanoma also are discussed.