A case-control analysis and laboratory study of the two feet-one hand syndrome in two dermatology hospitals in China

Tinea pedis: an updated review

Background

Tinea pedis is one of the most common superficial fungal infections of the skin, with various clinical manifestations. This review aims to familiarize physicians with the clinical features, diagnosis and management of tinea pedis.

Methods

A search was conducted in April 2023 in PubMed Clinical Queries using the key terms 'tinea pedis' OR 'athlete's foot'. The search strategy included all clinical trials, observational studies and reviews published in English within the past 10 years.

Results

Tinea pedis is most often caused by Trichophyton rubrum and Trichophyton interdigitale. It is estimated that approximately 3% of the world population have tinea pedis. The prevalence is higher in adolescents and adults than in children. The peak age incidence is between 16 and 45 years of age. Tinea pedis is more common amongst males than females. Transmission amongst family members is the most common route, and transmission can also occur through indirect contact with contaminated belongings of the affected patient. Three main clinical forms of tinea pedis are recognized: interdigital, hyperkeratotic (moccasin-type) and vesiculobullous (inflammatory). The accuracy of clinical diagnosis of tinea pedis is low. A KOH wet-mount examination of skin scrapings of the active border of the lesion is recommended as a point-of-care testing. The diagnosis can be confirmed, if necessary, by fungal culture or culture-independent molecular tools of skin scrapings. Superficial or localized tinea pedis usually responds to topical antifungal therapy. Oral antifungal therapy should be reserved for severe disease, failed topical antifungal therapy, concomitant presence of onychomycosis or in immunocompromised patients.

Conclusion

Topical antifungal therapy (once to twice daily for 1-6 weeks) is the mainstay of treatment for superficial or localized tinea pedis. Examples of topical antifungal agents include allylamines (e.g. terbinafine), azoles (e.g. ketoconazole), benzylamine, ciclopirox, tolnaftate and amorolfine. Oral antifungal agents used for the treatment of tinea pedis include terbinafine, itraconazole and fluconazole. Combined therapy with topical and oral antifungals may increase the cure rate. The prognosis is good with appropriate antifungal treatment. Untreated, the lesions may persist and progress.

Cutaneous Fungal Infections in Patients Experiencing Homelessness and Treatment in Low-Resource Settings: A Scoping Review

Patients experiencing homelessness (PEH) suffer from a high burden of cutaneous fungal infections. Preventative treatment is important as such infections can lead to harmful complications such as cellulitis and even osteomyelitis. There are sparse data regarding cutaneous fungal infections of homeless populations and management in low-resource settings. A MEDLINE search was conducted using the key terms "cutaneous," "fungal," "infections," "dermatophytes," and "homeless." The search included case-control, cohort, and randomized controlled trials published in the English language. This scoping review of studies yielded information with regard to practical treatment advice for providers in low-resource settings, including medical, hygiene, prevention, and treatment options for PEH with cutaneous fungal infections, the most common of which were tinea pedis (3-38%) and onychomycosis (1.6-15.5%). Few studies have been conducted on the differences between sheltered and unsheltered homeless patients, which can have treatment implications. Systemic antifungal therapy should be carefully considered for diffuse, refractory, or nail-based cutaneous fungal infections if there is a history of alcohol use disorder or liver disease. While PEH have a high risk of alcohol use disorder, this can make definitive treatment challenging.

Two Feet-One Hand Syndrome

Ringworm infection is a common but frequently misdiagnosed skin disease. An 81-year-old woman presented with a complaint of mild itch of the third and fourth fingers of her right hand and the toes of both feet. A crusted rash was seen on the right hand and both feet. The results of potassium hydroxide testing were positive for filamentous fungi. The diagnosis of two feet-one hand syndrome was made. The rash was treated successfully by topical ketoconazole. Recognition of this typical distribution of the rash may help make a prompt diagnosis of ringworm infection.

Two Feet-One Hand Syndrome: A Case Report / Sindrom dva stopala i jedne šake – prikaz slučaja

Two feet-one hand syndrome is a superficial fungal infections of the skin which involves both feet and one hand. Trichophyton rubrum and occasionally Trichophyton mentagrophytes are the usual causative organisms.

We present a 32-year-old healthy man with sharply demarcated papular erythematous and squamous lesions on dorsal aspect of the feet and diffuse dry scaling lesions of the right palm. In this syndrome, the development of tinea pedis generally precedes the development of tinea manus, which usually occurs on the hand that excoriated the pruritic feet or picked the toenails with onychomycosis. Our patient often used his dominant right hand to scratch the feet.

On mycological examination, fungal spores and mycelia were present and Trichophyton mentagrophytes was isolated. The patient was treated with itraconazole 200 mg daily for two weeks and topical terbinafine cream for four weeks. After the treatment all lesions resolved and fungal culture was negative.

Early diagnoses and treatment of tinea pedis and education about prophylaxis, constant care and regular medical assistance would minimize this problem in predisposed individuals.

Mycology - an update part 2: dermatomycoses: clinical picture and diagnostics

Most fungal infections of the skin are caused by dermatophytes, both in Germany and globally. Tinea pedis is the most frequent fungal infection in Western industrial countries. Tinea pedis frequently leads to tinea unguium, while in the elderly, both may then spread causing tinea corporis. A variety of body sites may be affected, including tinea glutealis, tinea faciei and tinea capitis. The latter rarely occurs in adults, but is the most frequent fungal infection in childhood. Following antifungal treatment of tinea unguium and also tinea capitis a dermatophytid or hyperergic reaction to dermatophyte antigens may occur. Yeast infections affect the mucous membranes both of the gastro-intestinal system and the genital tract as candidiasis mostly due to Candida albicans. Cutaneous candidiasis affects predominantely the intertriginous regions such as groins and the inframammary area, but also the intertriginous space of fingers and toes. In contrast, pityriasis versicolor is a superficial epidermal fungal infection primarily on the the trunk. Mold infections are rare in dermatology; they play a role nearly exclusively in nondermatophyte-mold (NDM) onychomycosis. The diagnosis of dermatomycoses comprises the microscopic detection of fungi using the potassium hydroxide preparation or alternatively the fluorescence optical Blankophor preparation together with culture. The histological fungal detection with PAS staining possesses a high sensitivity, and it should play a more important role in particular for diagnosis of onychomycosis. Molecular biological methods, based on the amplification of fungal DNA with use of specific primers for the distinct causative agents are on the rise. With PCR, such as dermatophyte-PCR-ELISA, fungi can be detected directly in clinical material in a highly specific and sensitive manner without prior culture. Today, molecular methods, such as Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI TOF MS) as culture confirmation assay, complete the conventional mycological diagnostics.

Tinea pedis: the etiology and global epidemiology of a common fungal infection

Tinea pedis, which is a dermatophytic infection of the feet, can involve the interdigital web spaces or the sides of the feet and may be a chronic or recurring condition. The most common etiological agents are anthropophiles, including Trichophyton rubrum sensu stricto, which is the most common, followed by Trichophyton interdigitale and Epidermophyton floccosum. There has been a change in this research arena, necessitating a re-evaluation of our knowledge on the topic from a multidisciplinary perspective. Thus, this review aimed to provide a solid overview of the current status and changing patterns of tinea pedis. The second half of the twentieth century witnessed a global increase in tinea pedis and a clonal spread of one major etiologic agent, T. rubrum. This phenomenon is likely due to increases in urbanization and the use of sports and fitness facilities, the growing prevalence of obesity and the aging population. For optimal patient care and management, the diagnosis of tinea pedis should be verified by microbiological analysis. In this review, we discuss the epidemiology, clinical forms, complications and mycological characteristics of tinea pedis and we highlight the pathogenesis, prevention and control parameters of this infection.

[Fungal nail infections--an update: Part 1--Prevalence, epidemiology, predisposing conditions, and differential diagnosis]

Onychomycosis describes a chronic fungal infection of the nails most frequently caused by dermatophytes, primarily Trichophyton rubrum. In addition, yeasts (e. g. Candida parapsilosis), more rarely molds (Scopulariopsis brevicaulis), play a role as causative agents of onychomycosis. However, in every case it has to be decided if these yeasts and molds are contaminants, or if they are growing secondarily on pathological altered nails. The point prevalence of onychomycosis in Germany is 12.4%, as demonstrated within the "Foot-Check-Study", which was a part of the European Achilles project. Although, onychomycosis is rarely diagnosed in children and teens, now an increase of fungal nail infections has been observed in childhood. More and more, diabetes mellitus becomes important as significant disposing factor both for tinea pedis and onychomycosis. By implication, the onychomycosis represents an independent and important predictor for development of diabetic foot syndrome and foot ulcer. When considering onychomycosis, a number of infectious and non-infectious nail changes must be excluded. While psoriasis of the nails does not represent a specific risk factor for onychomycosis, yeasts and molds are increasing isolated from patients with psoriatic nail involvement. In most cases this represents secondary growth of fungi on psoriatic nails. Recently, stigmatization and impairment of quality of life due to the onychomycosis has been proven.