INTRODUCTION
In the US, tinea pedis is the most common inflammatory fungal infection that is mostly caused by dermatophytes.1 These are the skin, hair, and nail-preferring fungi such as Trichophyton sp, Microsporum sp, and Epidermophyton sp, of which the top pedal pathogen is Trichophyton rubrum. Dermatophytes
are highly contagious and may be transferred between
soil, animals, humans, and fomites.
Wearing shoes, sneakers, and boots lead to creating a warm and moist environment, which is an optimal place for fungus to thrive. Traditionally, tinea pedis occurs in the pedal interdigital areas, where prolonged moisture will cause macerated tissue to occur, but it also presents on the plantar surface of the foot as dry, scaly, and itchy skin known as the moccasin type. Populations
at risk to develop tinea pedis include: those who use communal facilities (pools, dorm showers, gyms); those who wear rubber or non-breathable material shoes at work; and those who are obese, diabetic, immunocompromised, vascularly
compromised, or are unable to perform regular foot hygiene.
Treatment options have consisted of both prescription and over the counter topical medications as first line agents (such as naftifine, econazole, and ciclopirox), oral medications for recalcitrant
and severe presentations (off label uses for terbinafine, itraconazole, and on label for griseofulvin ultra micro-sized), and patient education on proper foot hygiene. Even after educating the patient on the basics of pedal hygiene (drying between
toes, changing socks and shoes daily, disinfecting family
showering areas, and wearing shower shoes in communal areas),
the physician will typically continue to manage the patient for a persistent and irritating plantar infection weeks to months after treating the initial infection.
Even though interdigital tinea pedis is classically described as the most common clinical presentation, many physicians agree that the moccasin type is widely seen and a challenge to treat.2 As described earlier, moccasin tinea pedis presents on the plantar foot commonly extending from the digital sulcus
to the medial, lateral, and posterior borders of the foot where it may reach superiorly towards the junction of the dorsal
and plantar skin. It can present as dry serpiginous scale, but may also be hyperkeratotic and in some cases, fissure. Scaling can be fine or coarse, and erythema may be present. Long standing moccasin tinea pedis is often asymptomatic and can predispose the patient to developing onychomycosis.
It may co-present with tinea manuum where the patient exhibits bilateral tinea pedis and unilateraly tinea manuum (2 feet–1 hand syndrome).
In the last few years, new topical antifungals have emerged for the treatment and management of tinea pedis, but all have been investigated and approved for the treatment of interdigital tinea pedis. Moccasin tinea pedis has not been recognized by the FDA as a definable and treatable disease entity separate from interdigital tinea pedis at this time. Thus, creating randomized, controlled clinical trials to investigate
moccasin tinea pedis is a challenge without an agreed
