Journal of Cosmetic Dermatology, 12, 254--260 Ultrastructure study of hair damage after ultraviolet irradiation Nehal Mohamed Zuel-Fakkar, MD, 1 Ekramy Ahmed El Khateeb, MD, 2 Hala Sobhi Cousha, MD, 3 & Dina Mohamed Hamed, MSc 4 1 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Ain Shams University, Cairo, Egypt 2 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Ain Shams University, Cairo, Egypt 3 Department of Pathology, Faculty of Medicine, Ain Shams University, Cairo, Egypt 4 Department of Dermatology, Faculty of Medicine, Ain Shams University, Cairo, Egypt Summary Background Natural ultraviolet exposure induces hair damage, which is difficult to avoid. Most of the research work is focused on the effect of ultraviolet on the epidermis, dermis as well as the immune system, whereas the long-term effect of ultraviolet on hair has not been investigated. Aim: we performed our experiment to find out the changes induced in hair follicle and shaft in those patients exposed to high doses of ultraviolet (A and B) during treatment of other skin conditions. Patients and Methods Light and transmission electron microscopy examination of scalp hair follicles and shafts of 10 patients with vitiligo under psoralen plus ultraviolet A (group 1) and 10 patients with vitiligo under narrow band ultraviolet B (group 2) was carried out and compared with those of 10 healthy volunteers (group 3). Results Physical changes in the appearance of hair were more in groups 1 and 2 than control. Reduced hair follicle thickness and perifollicular infiltrate and hyaline disorganized perifollicular collagen were observed more in group 1 than in group 2 with the absence of these changes in group 3. Transmission electron microscopy showed nonspecific cell injury in hair follicles in group 1 more than the other 2 groups, while the damaging effect on hair was more in the second group than the others. Conclusion Due to the damaging effect of ultraviolet on hair, patients under treatment with this modality should be cautious to protect their hair during treatment. Keywords: narrow band-ultraviolet B, psoralen and UVA, hair Introduction Human hair is constantly subjected to repeated envi- ronmental assaults, commonly termed weathering, which is aggravated by various extrinsic damages among which sunlight plays an important role. 1 Pro- longed exposure to ultraviolet radiation (UVR) causes dramatic changes to the physical properties of human hair. In extreme cases, irradiation can cause the whole cuticular layer to disintegrate exposing the cortex. 2 Ultraviolet bands vary in their penetrating ability to the skin according to their wave length. In general, they do not reach the deeply situated hair follicle mela- nocytes, and consequently, the stimulatory effect of UVR on these melanocytes may be through an indirect mechanism rather than a direct stimulation. 3 Ultraviolet B (UVB) maintains in the cuticle area and is responsible for hair protein loss, while ultraviolet A Correspondence: N M Zuel- Fakkar, 3 Kolyet el Banat Buildings, Nasr City, Cairo, Egypt. E-mail: nehalzf@hotmail.com Accepted for publication August 25, 2013 254 © 2013 Wiley Periodicals, Inc. Original Contribution