Fungal diseases, especially superficial and cutaneous forms (dermatophytes) are of great public health importance due to the possibility of transmission from people to others, especially where people live in groups. Lack of knowledge about how to prevent the transmission of these diseases can cause them to be transmitted to numerous people and carry a large financial burden and even significantly reduce the efficiency of people. Therefore, informing different segments of society about the prevalence of fungal diseases, ways and symptoms of its infection, ways to prevent its transmission to others and necessary measures in case of infection, can play a significant role in promoting public health. Dermatophyte infections are one of the most important health problems in the world and affect millions of people worldwide. It is estimated that 10-20% of people will develop these infections in their lifetime. The distribution of these infections varies in different countries in the world and it is more prevalent in developing countries than in industrialized countries. So far, more than 40 species of dermatophytes have been identified, which are classified into three genera: Microsporum, Trichophyton, and Epidermophyton. Dermatophytosis infection has several clinical forms that are classified according to the location of the infection; fungal infection of the feet, arms, legs, trunk, hands, palm and groin area, the scalp and hair the fingernails and toenails, and the nail bed. In addition to dermatophytes, other filamentous fungi can cause superficial and cutaneous infections. Yeasts such as Candida can also cause superficial and cutaneous infections. These diseases always cause problems such as pain, discomfort, disability, time consuming and high treatment costs. To combat dermatophytosis, it is necessary to know the regional dermatophytes and the extent of their spread, and also having instructions for the prevention of fungal diseases that its implementation can be effective in reducing these diseases.

Dermatophytosis is a prevalent mycologic skin disease which is a widespread important health problem in the world. The ecology and etiology of the disease are important issues for its control.

In a descriptive study, 341 patients with suspected dermatophytosis were examined over a period of one year (2004-2005). Skin, hair and nail samples were evaluated by to direct microscopic examination using potassium hydroxide (KOH) the specimens were cultured in sabouraud dextrose agar. In some cases, differential tests such as corn meal agar, urease and hair perforation were used for recognizing the isolated dermatophytes.

A total of 116 dermatophytes (34%) were isolated. Tinea cruris (31.9%) was the most common type of infection, followed by tinea corporis (20.7%), tinea pedis (19%), tinea unguium (11.2%), tinea faciei (7.7%), tinea manuum (5.2%), tinea capitis (4.3%). Epidermophyton floccosum was the most frequent isolated dermatophyte (32.8%). Also Dermatophytosis was more frequent in male gender.

The anthropophilic species, E. floccosum, was the most common causative dermatophyte of tinea in Qazvin and the most common clinical type of dermatophytosis was Tinea cruris.