Dermatophytes are species with slight genetic variation, and are yet several uncertainties about the differences among species. This study aims to isolate and diagnose the Trichophyton interdigitale by molecular technique and to reveal the phylogenetic distance and similarity of the Iraqi isolates to other isolates from the globe, in addition, to submit the obtained sequences to the NCBI database. This study included 86 with multiple lesions on different parts of the body. The results showed different variations within the ITS gene between the isolates. It was concluded that Trichophyton interdigitale in Iraqi isolates had two types of substitution variations (Transition and Transversion) different than global isolates. Moreover, it appeared according to the phylogenetic tree, the similarity was 97% with isolates from the Czech Republic and Japan, whereas 98% with the isolates from France and Germany. Keywords. Dermatophytes, genetic variations, ITS gene, multiple lessons
