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Published in Ashfaq A Marghoob, Ralph Braun, Natalia Jaimes, Atlas of Dermoscopy, 2023
Anna Waśkiel-Burnat, Lidia Rudnicka, Małgorzata Olszewska, Adriana Rakowska, Ralph M. Trüeb, Isabel Kolm
Hair shaft abnormalities result from genetic conditions and/or exogenous factors affecting the integrity of the hair shaft. Hair shaft abnormalities can occur as a localized or generalized disorder. Classic diagnosis is based on the microscopic examination of the hair shaft. Trichoscopy is an effective tool for a rapid diagnosis of both congenital and acquired hair shaft disorders. Hair shaft abnormalities that can be visualized by dermoscopy include monilethrix, pili torti, pili canaliculi et trianguli, pili annulati, trichorrhexis invaginata, trichorrhexis nodosa, and acquired features, such as micro-exclamation mark hairs, comma hairs, or vellus hairs.
Hair and hairy scalp
Published in Richard Ashton, Barbara Leppard, Differential Diagnosis in Dermatology, 2021
Richard Ashton, Barbara Leppard
The three phases of the hair cycle are: Anagen (80–90% of hairs). This is the growing phase and on the scalp lasts 2–6 years.CatagenThe hair matrix cells stop dividing and hair growth stops. It lasts about 2 weeks.Telogen (10–20%) This is the resting phase. The hair shaft moves up in the dermis. It lasts 3 months and at the end of that time the hair is shed.
Lasers and New Technologies in Hair Diseases
Published in Rubina Alves, Ramon Grimalt, Techniques in the Evaluation and Management of Hair Diseases, 2021
Giselle Martins Pinto, Patricia Damasco
Side effects include transient post-treatment mild erythema, mild painful and burning sensation. Some breakage of hair shaft can occur, too. However, most of the cases do not complain none of them. The majority of complications associated with laser resurfacing are not linked to laser type, but rather to the depth of cutaneous damage, which in turn is linked to the excessive number of passes, density (the number of microscopic thermal lesions per area), pulse duration, and fluence used.
Comparative study between follicular unit transplantation with intact and non-intact hair bulb in treatment for stable vitiligo
Published in Journal of Dermatological Treatment, 2022
Yuchong Chen, Jianna Yan, Xuewen Chen, Leimeng Gan, Min Song, Jue Wang, Hongxia Shen, Hao Luo, Long Jiang, Xi Luo, Xiaogang Chen, Yichen Tang
Vitiligo causes a partial or total destruction of melanocytes, initially only of the epidermis and later even of the hair follicles known as leukotrichia. The follicle is known as the last reservoir of melanocytes in vitiligo. Transplantation of normal follicles could provide melanocytic cells to previously vitiliginous areas. Several studies had shown that hair transplantation was a treatment option for vitiligo (4–6). Hair transplantation always treated the vitiligo in scalp or pubis in these studies, because it could cause hairy appearance. The characteristics of the hair shaft were controlled by the dermal papilla around with hair bulb. Whether the hair shaft would become thinner when the follicle hair bulb was dissected partially? Whether the transplantation of follicle with non-intact hair bulb could re-pigmentated normally? It is a benefit for patients with vitiligo to get pigmentation with less hairy appearance. The current study aimed to compare the efficacy and cosmetic of transplantation of follicles with intact and non-intact hair bulb in the treatment of patients with stable vitiligo.
Investigation of optimum transplant and extraction density based on the data from the donor area of Chinese androgenetic alopecia patients: a multicenter, retrospective study
Published in Journal of Cosmetic and Laser Therapy, 2020
Bensen Sun, Shu Zhang, Sushmita Pradhan, Wenbin Zhao, Yuxian Xu, Xinyi Zhang, Yongfeng Diao, Xian Jiang
The model of hair planting was built as following (Figure 2a). The area of planting or harvesting is considered as a horizontal plane. The direction of the hair shaft is parallel to the plane. The horizontal projection of the hair shaft is parallel to the side of the square. Hypothetically, the length of each side of the square is denoted as l, the length of the hair is α, the diameter of the hair is d, and the angle between the hair and the plane is θ, where θ’ stands for the complementary aspect of the angle θ. Hence the minimum number (N) of hair to cover a square can be attained. In this formula (Figure 2b), “[x]” denotes the smallest integer greater than or equals to “x”. Additionally, the maximum potential hair extraction in the SDA can be achieved by this formula.
Advances in understanding of Netherton syndrome and therapeutic implications
Published in Expert Opinion on Orphan Drugs, 2020
Evgeniya Petrova, Alain Hovnanian
The diagnosis of NS is often difficult in early infancy because the clinical presentation of erythroderma with failure to thrive is common with other conditions, such as immune deficiency syndromes. The absence of hair or the delayed onset of hair abnormalities precludes the search for TI, and atopic manifestations and ILC have not developed yet. In children and in adults, specific hair abnormalities are usually present, and their association with atopic manifestations, IE or ILC is highly suggestive of NS. As hair shaft defect is not always present even in severe NS patients, the clinical frequency of NS could be higher. Therefore, diagnosis is routinely confirmed by histology and molecular analyses.