General medications for dermatophyte infections include topical ointments. Tinea corporis is caused by a tiny fungus known as dermatophyte. Achorion is an obsolete genus of dermatophyte fungus. Terbinafine is mainly effective on the dermatophyte group of fungi. When onychomycosis is due to a dermatophyte infection, it is termed tinea unguium. "Trichophyton rubrum" is the most common dermatophyte involved in onychomycosis. The ring shape of dermatophyte lesions result from outward growth of the fungi. Onychocola canadensis is a relative of the dermatophyte and an occasionally causes onychomycosis. "Trichophyton concentricum" is an anthropophilic dermatophyte, meaning, humans are its primary host. Examples are the "Gymnoascus", "Talaromyces" and the dermatophyte "Arthroderma". The dermatophyte&colon;genus "Langeronia" () is named after him. It is a type of dermatophyte that colonizes keratinized tissues (primarily hair) causing infection. If the fungus is a dermatophyte, the medium will turn bright red. Usually, dermatophyte infections can be diagnosed by their appearance. If the fungus is not a dermatophyte, no color change will be noted.