dermatomycoses among students in a school dormitory in semnan

background: dermatomycoses are a major public health problem. tinea cruris is a form of dermatomycoses.tinea cruris is a common infection in the groin area, genitals, pubic area, perineum and perianal skin.the purpose of thisstudywas to investigate the cutaneous fungal infections among students in a school dormitory. materials and methods: the study was performed on 110 male students dormitory aged between  18 to 28 years.from the specimens obtained, direct preparations were made using %10 potassium hydroxide and cultured on sabouraud dextrose agar containing 0.05 mg/ml chloramphenicoland 0.5 mg/ml cycloheximide (scc). identification of fungi was performed according to morphologic and microscopic growth of the colonies and using slide culture method. results: 17 people out of 110 individuals were diagnosed with cutaneous fungal infections. six people were diagnosed with dermatophytosis. all cases of dermatophytosis were tinea cruris. epidermophyton floccosum, the anthropophilic species, was only isolated dermatophyte.the prevalence of tinea cruris was 5.5% and the prevalence of pityriasis versicolor was 4.5%. conclusion: the most important source of transmission of anthropophilic dermatophyte species was by men to men.the results of this study is similar to most other studies in iran and other countries. in addition to treatment, other necessary steps should be applied in order to prevent infection and reduce the risk of pathogens.