RESUMEN
Our aim was to investigate the microscopic surface structural alteration in hair with hereditary trichodysplasia. This article presents the results of light and scanning electron microscopy [SEM] examination of cases having hereditary trichodysplasia. The biopsy specimens were obtained from 2 girls of ages 3 and 5-years, Department of Pediatrics, Faculty of Medicine, Hacettepe University in 2001. A large number of hair specimens were obtained from these 2 cases having hereditary trichodysplasia. Routine light microscopic and SEM procedure was performed on the tissue specimen, and then they were examined by light microscopy and SEM. Hair specimens taken from both patients had great similarities. Our results reveal that the atypical looking hair were flattened, twisted and partly scattered at the end. Moreover, these hairs had sheath structures with abnormal proliferation and these structures were damaged, the cuticles had fractures and were degenerative. There is only a small number of SEM studies in literature reporting the ultrastructural changes of hereditary trichodysplasia. Scanning electron microscopy is a 3 dimensional examination technique revealing easily comparable images and it is indispensable for diagnosis in various tissues which permit considerable magnification. As it is used in the hereditary trichodysplasia syndrome its routine usage in many dermatologic and hair diseases will result in valuable contributions to scientific literature