Dermatophytes are fungi capable of digesting keratin and able to infect the skin surface of animal. Among them, the anthropophilic species Trichophyton rubrum is the most important human pathogen in Japan as the causative species of tinea lesions. The lesions caused by this fungus are known to be mild in their inflammatory reaction. More than 20% of the Japanese population is believed to be suffering from tinea pedis and the situation has not changed despite the introduction of new potent antifungal drugs. Several attempts made to cultivate the fungus on the skin surface has revealed the presence of pathogenic dermatophytes in healthy looking skin around a lesion or on the skin of surrounding individuals. Also, more than half of tinea pedis patients are left untreated or are treated intermittently only when the patient has noticed uncomfortable symptoms due to a lesion. The low QOL impairment due to tinea pedis lesions by anthropophilic dermatophytes is one reason preventing complete cure and has resulted in a growing number of tinea pedis patients, especially among the aged. To achieve control of the infections by anthropophilic dermatophytes, the ecological background of the causative fungi should be taken under consideration rather than their eradication.