Related Experiment Video
Updated: May 5, 2026

Application of Laser Micro-irradiation for Examination of Single and Double Strand Break Repair in Mammalian Cells
Published on: September 5, 2017
Ultrastructure study of hair damage after ultraviolet irradiation
Nehal Mohamed Zuel-Fakkar1, Ekramy Ahmed El Khateeb, Hala Sobhi Cousha
1Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
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.
Related Concept Videos
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Nucleotide Excision Repair
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Accessory Structures of the Skin: Hair Growth and Types

