A Foot in the Door for Dermatophyte Research

Dermatophytes are a group of filamentous fungi that cause infections of the skin (see Figure 1 for diseases, Figure 2 for typical dermatophyte species). Diseases caused by dermatophytes include athlete’s foot, ringworm, jock itch, and nail infections (onychomycosis). The medical terminology for dermatophyte infections is to use the word tinea (to denote a fungal infection of the skin) followed by a word that describes the site of infection. For example, tinea pedis refers to athlete’s foot and tinea capitis is scalp ringworm. In general, dermatophytes remain localized to keratinized surfaces such as skin, hair, and nails and do not invade deeper tissues. That said, dermatophyte infections in immunocompromised patients can be quite severe. Dermatophytes are grouped into three general categories based on their natural environment: anthropophilic (live exclusively on humans), zoophilic (live on an animal host), and geophilic (live in the soil) [1]. The majority of human infections are caused by anthropophilic species; however, species from all three groups have been associated with human disease. For example, pets with ringworm can transmit the infection to their owners, and stray cats carrying dermatophytes are considered to be a vector for infection in several eastern and southern European countries [2].