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Diseases of the Hair
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Rodney Sinclair, Wei-Liang Koh
Clinical presentation: For congenital localized hypertrichosis, this can be an isolated finding with a discrete circumscribed patch of increased terminal hairs, or associated with a congenital melanocytic nevus, Becker’s nevus, or underlying spinal dysraphism (faun tail sign at lumbosacral region). For congenital generalized hypertrichosis, patients rarely can present with increased body hair from birth, either lanugo hair (congenital hypertrichosis lanuginosa) or terminal hair (congenital hypertrichosis terminalis). This can be an isolated finding or associated with other congenital syndromes (e.g., Hurler syndrome, Cornelia de Lange syndrome). For acquired localized hyper-trichosis, this can be a feature in porphyria cutanea tarda. This can also occur in pretibial myxedema plaques, usually associated with Graves’s disease. Topical medications, for example, minoxidil, bimatoprost, and potent topical steroids, can induce hair growth. Repetitive rubbing/scratching and application of plaster cast can also result in localized hypertrichosis. For acquired generalized hypertrichosis, this condition can be associated with underlying malignancies (“malignant down,” reported rarely in gastrointestinal, lung, breast cancers), hypothyroidism, eating disorders (e.g., anorexia nervosa, bulimia), dermatomyositis, dystrophic epidermolysis bullosa, and certain drugs (e.g., minoxidil, phenytoin, cyclosporine).
What You Need for a Trichology Consultation
Published in Rubina Alves, Ramon Grimalt, Techniques in the Evaluation and Management of Hair Diseases, 2021
Oscar Muñoz Moreno-Arrones, Sergio Vañó Galván
For the treatment of hair disorders, local drug infiltration may be necessary. It is especially useful to have corticosteroids ready to be infiltrated to any autoimmune alopecia. There are essentially two corticosteroids that are used for infiltration: triamcinolone acetonide and mometasone acetate. While the procedure and concentration of intralesional corticosteroid administration escapes the objective of this chapter, we must mention that we prefer the use of the corticosteroid diluted in an amide anaesthetic (usually lidocaine 5%) in an insulin syringe (30 G, 1 mL). In addition, other molecules can be administered to stimulate hair growth. In general, these drugs (e.g. dutasteride or minoxidil) must be formulated in excipients for their correct stability at the time of administration. Usually 1-mL luer-lock syringes are used, which are then attached to 30 G 0.30 × 4 mm needles (Figure 18.3). The administration of local anesthetics may be indicated prior to some procedures such as mesotherapy. It may be especially useful to have amides such as mepivacaine and lidocaine rapidly available to anesthetize the area. Both lidocaine and mepivacaine are excellent anesthetics due to their rapid action and safety. We usually inject them into syringes and needles of similar characteristics to the previously mentioned drugs.
The Shaven (Sha) Mutation, Chromosome 15
Published in John P. Sundberg, Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
Homozygous (Sha/Sha) mice can be identified at birth by the paucity and wavy appearance of vibrissae. The first hair coat does not appear by the time of weaning. Thickening and pigmentation of skin proceeds normally. By 14 days of age, only a few short hairs are evident on the feet and head (Figure 2). Hair growth becomes evident between 28 and 34 days of age with the development of short fuzzy hairs, primarily on the head and anterior back. Cyclic regeneration of the short fuzzy hairs and abnormal vibrissae proceeds in the normal anterior-posterior manner. Nails are occasionally deformed.
Microneedle mediated transdermal delivery of β-sitosterol loaded nanostructured lipid nanoparticles for androgenic alopecia
Published in Drug Delivery, 2022
Kousalya Prabahar, Ubaidulla Udhumansha, Nehal Elsherbiny, Mona Qushawy
The hair growth was observed by qualitative evaluation. After 21 days, the difference in hair growth in each group was examined visually and photographed. A quantitative analysis of hair growth was performed. After shaving the long hair, the animal skin in the dorsal area was dissected and fixed in 10% formalin (Dhanotia et al., 2011). Vertical sections of the skin were prepared after fixation and stained with hematoxylin and eosin (H&E). To evaluate hair growth, the sections were analyzed for various parameters. The follicular density (number of follicles/mm) was reported by recording the number of hair follicles in 2 mm area. Anagen/telogen ratio was determined by calculating the number of follicles in anagen phase (active growth phase) and telogen phase (resting phase) (Noubarani et al., 2014).
Impact of a nutritional supplement during gestation and early childhood on child salivary cortisol, hair cortisol, and telomere length at 4–6 years of age: a follow-up of a randomized controlled trial
Published in Stress, 2020
Brietta M. Oaks, Seth Adu-Afarwuah, Sika Kumordzie, Mark L. Laudenslager, Dana L. Smith, Jue Lin, Rebecca R. Young, Charles D. Arnold, Helena Bentil, Harriet Okronipa, Maku Ocansey, Kathryn G. Dewey
A small amount of hair (roughly the diameter of a pencil eraser and estimated to be at least 25 mg) was cut by the study nurse from the posterior vertex region close to the scalp. Typically, hair is estimated to grow 1 cm/month (Stalder et al., 2017); however, slower hair growth rate has been observed for persons of African descent (at an average rate of 0.80 cm/month) (Loussouarn, 2001). We therefore attempted to collect at least 1.6 cm of hair to estimate cortisol accumulation over the previous two months. Hair samples were wrapped in foil and stored at room temperature until shipped to the University of Colorado Anschutz Medical Center for analysis. Hair was ground, cortisol was extracted, and then measured by immunoassay (Salimetrics, LLC, State College, PA) according to previously published methods with average intra and inter-assay CVs 2.7% and 13.3%, respectively (Hoffman, Mazzoni, Wagner, Laudenslager, & Ross, 2016; Lehrer, Dubois, Maslowsky, Laudenslager, & Steinhardt, 2016).
The “in’s and outs” of laser hair removal: a mini review
Published in Journal of Cosmetic and Laser Therapy, 2019
Mandy M. Thomas, Nicolette N. Houreld
Laser hair removal relies on three paramount parameters: the proper selection of wavelength in the recommended visible to near-infrared (NIR) region up to about 1100–1200 nm; pulse duration (in milliseconds, ms); and the energy density or fluence (in joules per square centimetre, J/cm2) administered, which is related to total exposure time (10). Thermal injury can be restricted to the target chromophore through the selection of the correct parameters. One other important concept is the thermal relaxation time (TRT). TRT is defined as the time required by an object to cool down to 50% of the initial temperature achieved (11). For targeted tissue damage to occur, photons at the correct wavelength need to be absorbed by the chromophore and not the adjacent tissue. In order to achieve this, the pulse duration should be less than the TRT of the target. If the pulse duration exceeds the TRT, not only will the target be damaged, but the heat energy will also dissipate to the adjacent tissue resulting in injury to the surrounding area. Additionally, the stage of hair growth also plays an important factor. The ideal stage in the hair growth cycle is the active anagen phase, as there is an abundance of melanin and the follicles are located deep within the skin and are still attached to the papilla for nourishment. It is estimated that a 20% reduction may be observed with each treatment if hair growth is in the anagen phase and if the correct laser/light parameters are used.