Onychomycosis: Recognition, Diagnosis, and Management

Abstract

About 20% of the US population between the ages of 40 and 60 years have fungal nail disease, or onychomycosis. The incidence of this infection is increasing worldwide. Most cases of onychomycosis in the United States are caused by dermatophytes, but nondermatophyte fungi (molds or yeasts) may also be causative agents. To confirm the diagnosis of onychomycosis, a potassium hydroxide examination should be performed. A culture is necessary to determine the fungal pathogen and to aid in selecting appropriate therapy. Worldwide, fluconazole (not yet approved in the United States for onychomycosis), itraconazole, and oral terbinafine have superseded griseofulvin and ketoconazole as the agents of choice in treating onychomycosis. These newer systemic compounds have higher cure rates and cause fewer side effects than traditional agents. Intermittent dosing with itraconazole (3 or 4 one-week pulses of 200 or 400 mg daily) is the latest advance in the treatment of onychomycosis. This regimen has been found to be at least as safe and effective as short-term continuous therapy, yet more flexible, convenient, and economical.

Eco-epidemiologic study of emerging fungi related to the work of babaçu coconut breakers in the State of Maranhão, Brazil

“…Most authors have frequently identifi ed dermatophytes as agents (80 to 90%), followed by yeasts (5 to 17%) and nondermatophytic fi lamentous fungi (2 to 12%) 17,18 , in agreement with the present study.…”

Freqüência das dermatofitoses em exames micológicos em Hospital Geral de Porto Alegre, Brasil

“…As onicomicoses representam de 18 a 40% das onicopatias 4 e têm sua prevalência aumentada em adultos e idosos, principalmente em pacientes com diabetes mellitus. 8,[12][13][14][15][16][17] Outras situações, ou doenças de base, contribuem para o aparecimento de dermatofitoses, como em pacientes com Aids, síndrome de Down, uso de corticosteróides e drogas imunossupressoras em transplantados. 17,18 O grupo é composto pelos gêneros Trichophyton sp, Microsporum sp e Epidermophyton floccosum, que podem ser diferenciados de acordo com as características macroscópicas e microscópicas das culturas.…”

“…O Trichophyton rubrum é o agente antropofílico mais freqüentemente isolado na Europa, América do Sul e América do Norte. 2,5,6,9,10,13,16,18,19 Para o diagnóstico das dermatofitoses é importante observar o local da coleta, preferencialmente nas regiões periféricas, onde se encontram os elementos fúngicos mais ativos, e nas lesões ungueais no limite entre a parte normal e a afetada. 18 Algumas culturas negativas podem ter explicação em uma possível inviabilidade das hifas e artroconídios observados no exame direto, na contaminação da cultura com fungos saprófitas, apesar do uso de meio seletivo ou ainda por técnica de cultivo inadequada.…”

Non-Dermatophyte as Pathogens of Onychomycosis among Elderly Diabetic Patients

“…Total dystrophic onychomycosis (TDO) has been reported as the most destructive clinical form representing the end result of the evolution of any of the other five clinical forms in our study, this clinical presentation occurred in 44 cases, suggesting an advanced stage of the disease. In addition, the high number of involved toenails found on TDO cases also suggested a long-time exposure to pathogenic agents before sought for medical care [4].…”

“…Aging is one of the predisposing conditions to develop mycotic nails [1][2][3], those often present chronic health problems such as diabetes peripheral circulation In fact in the elderly [3,4], the normal structure of the nail is altered producing changes in the color, thickness, flexibility, and shape resulting in some cases to marked dystrophic disturbances, mainly on the toenails. Since most of the functions of the nails are lost, the nail is increasingly exposed to trauma [3,5] and consequently to bacterial and fungal infections.…”