International summit on cutaneous antifungal therapy. Boston, Massachusetts, Nov. 11-13, 1994

[Influence of nutrition, common autoimmune diseases and smoking on the incidence of foot mycoses]

BACKGROUND

Foot mycoses, including onychomycoses, are worldwide infectious diseases. As part of a regional survey using randomly selected residents of in Mecklenburg-Western Pomerania, we investigated the impact of dietary habits, the presence of most frequent autoimmune diseases and current smoking on fungal skin infections in order to reveal potential new risk factors to elucidate potential preventive interventions.

OBJECTIVES

The identification of potential new factors that influence the development of mycosis was performed in order to derive possible preventive measures.

METHODS

In the Study of Health in Pomerania (SHIP) in Mecklengburg-Western Pomerania, 2523 inhabitants were examined for mycotic lesions and asked about nutritional habits, the presence of atopic dermatitis, allergic rhinitis, psoriasis and smoking habits.

RESULTS

In all, 8% of probands were diagnosed with mycosis, 6.5% onychomycosis, 3.7% tinea pedis and 0.2% tinea corporis. Psoriasis, allergic rhinitis and atopic dermatitis and frequent consumption of cooked potatoes, oatmeal and corn flakes, cereals, pasta and rice were significantly associated with tinea pedis. Onychomycosis was positively associated with consumption of cooked potatoes. Cigarette consumption proved protective for tinea pedis and dermatophyte colonization.

CONCLUSIONS

The autoimmune disorders psoriasis and atopic dermatitis and allergic rhinitis seem to predispose to foot mycosis. Recalcitrant mycosis should raise the question of diets high in carbohydrates. Nicotine abuse seems to protect against skin mycosis and colonization.

Blad-containing oligomer: a novel fungicide used in crop protection as an alternative treatment for tinea pedis and tinea versicolor

PURPOSE

The lack of novel antifungal drugs and the increasing incidence and severity of fungal infections are major concerns worldwide. Herein, we tested the activity of the Blad-containing oligomer (BCO), a new antifungal molecule already in use for agriculture, on Malassezia spp. and dermatophytes, the causal agents of human tinea versicolor and tinea pedis. Given the lack of a standard method for Malassezia susceptibility testing and the plethora of published methods, we also developed an improved method for this genus.

METHODOLOGY

The efficacy of BCO was assessed in vitro and compared to that of the drugs currently utilized in the treatment of tinea versicolor (fluconazole and itraconazole) and tinea pedis (itraconazole and terbinafine). For dermatophytes, the standard microdilution broth-based method was used, with small adjustments, and several broth formulations and inocula sizes were tested to develop an improved susceptibility method for Malassezia spp.

RESULTS

We successfully developed a microdilution broth-based method with considerable advantages over other available methods, and used it for all in vitro susceptibility tests of Malassezia spp. isolates. We report that, on a molar basis, BCO was more effective than fluconazole or itraconazole on most strains of Malassezia spp. isolated from clinical samples (n=29). By contrast, BCO was less effective than itraconazole or terbinafine on the common dermatophytes Trichophyton rubrum and Trichophyton interdigitale.

CONCLUSION

These data place BCO as a promising drug for the treatment of Malassezia-associated skin diseases. Further in vivo studies are now required to ascertain its applicability in the clinical setting.

Fungal interdigital tinea pedis in Dakar (Senegal)

Fungal interdigital tinea pedis (FITP) is the most frequent dermatomycosis in industrial countries. In African tropics, it's a rare motive of consultation and is discovered while complicated. The aims of this article were: to determine the frequency of interdigital tinea pedis among overall mycological analysis in our laboratory; to study epidemiological, clinical and mycological aspects of FITP in outpatients attending the Le Dantec mycology laboratory in Dakar. A total of 62 males (60%) and 42 females (40%), mean age: 43.15 years (range: 11-81 years), were received from January 2011 to December 2015 for suspicion of FITP. Skin specimens were taken from all patients for microscopy and fungal culture. The frequency of ITP represents 5.6% (104/1851) among our overall mycological analysis. FITP was confirmed in 68 patients (SPI=65.38%), mainly located between the 4th and 5th toes and 71 fungal species were isolated (CPI=68.27%). Among patients with confirmed FITP, there were 38 males (56%) and 30 females (44%). The prevalence was highest in patients between 44 and 54 years (26%). Candida albicans, Fusarium solani and Trichophyton interdigitale were shown to be the most common pathogens respectively for yeasts (39%), non-dermatophytic filamentous fungi (NDFF; 21%) and dermatophytes (11%). So FITP isn't a common reason for consultation in Dakar but its simple parasitic index (SPI) is still very high and dermatophytes formerly the main causative agents are being relegated to third place behind yeasts and NDFF.

High prevalence of skin diseases and need for treatment in a middle-aged population. A Northern Finland Birth Cohort 1966 study

To determine the overall prevalence of skin diseases a whole-body skin examination was performed for 1,932 members (46-years of age) of the Northern Finland Birth Cohort (NFBC 1966), which is a comprehensive longitudinal research program (N = 12,058). A high prevalence of all skin diseases needing treatment was found (N = 1,158). Half of the cases of skin findings were evaluated to be serious enough to require diagnostic evaluation, treatment or follow-up either in a general health care, occupational health care or a secondary care setting. The remaining half were thought to be slight and self-treatment was advised. Males (70%) had more skin diseases needing treatment than females (52%) (P<0.001). The most common skin finding was a benign skin tumor, which was found in every cohort member. Skin infections (44%), eczemas (27%) and sebaceous gland diseases (27%) were the most common skin diseases in the cohort. Moreover, skin infections and eczemas were more commonly seen in the group with low education compared to those with high education (P<0.005). The results strengthen the postulate that skin diseases are common in an adult population.

A twenty-year survey of dermatophytoses in Braga, Portugal

BACKGROUND

Modifications in social habits together with the increase of emigration have contributed not only to increased dermatophytoses but also to an altered etiology. During the last few years, Braga has suffered a radical change from a rural to a cosmopolitan life-style.

METHODS

A statistical study of dermatophytoses and the etiology of their causative agents was performed by a retrospective survey carried out among patients of Hospital de São Marcos, Braga, Portugal, from 1983-2002. In this study, a total of 10,003 patients were analyzed.

RESULTS

Over this period the frequency of dermatophytoses, as defined by the recovery of a dermatophyte in culture, was found to be 23.6%, whereas nondermatophytic infections accounted for 7.0%. Analysis of the clinical forms and the isolated fungi supports that the dermatophyte species have a predilection for certain body areas (P <or= 0.01). Age is a very important factor regarding the occurrence of dermatophytoses (P <or= 0.0001), with a correlation between increasing age and infection, positive for Trichophyton rubrum and negative for Microsporum canis. Overall the gender of the patients is not an association factor for the development of dermatophytoses; however, significant differences were detected in the distribution of some etiologic agents (P <or= 0.05).

CONCLUSIONS

The results showed the main etiologic agent of dermatophytoses to be Trichophyton rubrum (37.4%). Moreover, dermatophytoses are both decreasing and showing a new profile in Braga, and a pronounced decrease of Trichophyton megninii was observed throughout the study.

Hyperhidrose als Risikofaktor der Tinea pedis

BACKGROUND

The purpose of this study was to evaluate a possible association between tinea pedis (interdigital mycosis) and hyperhidrosis by a case-control-study.

PATIENTS AND METHODS

30 otherwise healthy patients (age 22-56 years, 30% female) with mycologically proven tinea pedis and 51 control patients were included.

RESULTS

53.3% of the patients with tinea pedis and 33.3% of the control-patients had focal hyperhidrosis defined by gravimetry (definition as > or =30 mg sweat/min) (p-value=0.08). To control for possible confounding variables a multivariate analysis was performed including possible risk factors such as gender, regular visits in sauna and/or swimming pools. Multivariate analysis found a 3.5-fold increased risk for patients with tinea pedis to have hyperhidrosis.

CONCLUSION

The study supports an association between tinea pedis or interdigital mycosis and focal plantar hyperhidrosis and therefore lends credence to the treatment of hyperhidrosis in patients with tinea pedis.

Superficial fungal infections

Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of infection will be covered: tinea versicolor, piedra, and tinea nigra. Tinea versicolor is common worldwide and is caused by Malassezia spp, which are human saprophytes that sometimes switch from yeast to pathogenic mycelial form. Malassezia furfur, Malassezia globosa, and Malassezia sympodialis are most closely linked to tinea versicolor. White and black piedra are both common in tropical regions of the world; white piedra is also endemic in temperate climates. Black piedra is caused by Piedraia hortae; white piedra is due to pathogenic species of the Trichosporon genus. Tinea nigra is also common in tropical areas and has been confused with melanoma.

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.

Current management of fungal infections

The management of superficial fungal infections differs significantly from the management of systemic fungal infections. Most superficial infections are treated with topical antifungal agents, the choice of agent being determined by the site and extent of the infection and by the causative organism, which is usually readily identifiable. One exception is onychomycosis, which usually requires treatment with systemically available antifungals; the accumulation of terbinafine and itraconazole in keratinous tissues makes them ideal agents for the treatment of onychomycosis. Oral candidiasis in immunocompromised patients also requires systemic treatment; oral fluconazole and itraconazole oral solution are highly effective in this setting. Systemic fungal infections are difficult to diagnose and are usually managed with prophylaxis or empirical therapy. Fluconazole and itraconazole are widely used in chemoprophylaxis because of their favourable oral bioavailability and safety profiles. In empirical therapy, lipid-associated formulations of amphotericin-B and intravenous itraconazole are safer than, and at least as effective as, conventional amphotericin-B (the former gold standard). The high acquisition costs of the lipid-associated formulations of amphotericin-B have limited their use.

Rapid discrimination among dermatophytes, Scytalidium spp., and other fungi with a PCR-restriction fragment length polymorphism ribotyping method

Dermatomycoses are very common infections caused mainly by dermatophytes. Scytalidiosis is a differential mycological diagnosis, especially in tropical and subtropical areas. Since a culture-based diagnosis takes 2 to 3 weeks, we set up a PCR-restriction fragment length polymorphism (RFLP) method for rapid discrimination of these fungi in clinical samples. The hypervariable V4 domain of the small ribosomal subunit 18S gene was chosen as the target for PCR. The corresponding sequences from 19 fungal species (9 dermatophytes, 2 Scytalidium species, 6 other filamentous fungi, and 2 yeasts) were obtained from databases or were determined in the laboratory. Sequences were aligned to design primers for dermatophyte-specific PCR and to identify digestion sites for RFLP analysis. The reliability of PCR-RFLP for the diagnosis of dermatomycosis was assessed on fungal cultures and on specimens from patients with suspected dermatomycosis. Two sets of primers preferentially amplified fungal DNA from dermatophytes (DH1L and DH1R) or from Scytalidium spp. (DH2L and DH1R) relative to DNA from bacteria, yeasts, some other filamentous fungi, and humans. Digestion of PCR products with EaeI or BamHI discriminated between dermatophytes and Scytalidium species, as shown with cultures of 31 different fungal species. When clinical samples were tested by PCR-RFLP, blindly to mycological findings, the results of the two methods agreed for 74 of 75 samples. Dermatophytes and Scytalidium spp. can thus be readily discriminated by PCR-RFLP within 24 h. This method can be applied to clinical samples and is suited to rapid etiologic diagnosis and treatment selection for patients with dermatomycosis.

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.

Itraconazole in the treatment of tinea pedis and tinea manuum: comparison of two treatment schedules

A multicentre, randomized, double-blind, parallel-group trial was conducted to compare the efficacy and safety of two dosages of itraconazole in the treatment of tinea pedis or manuum. Of the 135 patients recruited, 66 received itraconazole 400 mg daily for 1 week and 69 received itraconazole 100 mg daily for 4 weeks. In the evaluable patients observed-case analysis, mycological cure was seen in 63% of patients in the 400 mg/1 week group and in 75% in the 100 mg/4 weeks group at the end of a 6-week follow-up period (not significantly equivalent). In the evaluable patients worst-case analysis and the intention-to-treat analysis, mycological cure rates in the two groups were borderline significantly equivalent at the end of follow-up (range 51-57%). Clinical response was seen in 81% of evaluable patients in the 400 mg/1 week group and in 75% in the 100 mg/4 weeks group at the end of follow-up; equivalence testing showed the 400 mg/1 week regimen to be at least equivalent to the 100 mg/4 week regimen. Similar results were found in the intention-to-treat analysis, and tolerability ratings for the two treatment regimens were significantly equivalent. This trial has shown that itraconazole 400 mg/1 week and itraconazole 100 mg/4 weeks are both effective regimens for the treatment of tinea pedis or manuum. The two treatment schedules were equally well tolerated and safe.

Isolation of fungi from onychomycosis-suspected nails by two methods: clipping and drilling

We examined 101 nails clinically suspected of onychomycosis by taking specimens with two different techniques: clipping and drilling. We then compared the mycological results of these two techniques. The microscopic results were similar, but culture was more successful with the clipping technique. Twenty-seven per cent of specimens obtained by clipping were culture positive for dermatophytes compared with 20% obtained by drilling and a combined positivity rate of 31%.