Nail anatomy and physiology
Archana Singal, Shekhar Neema, Piyush Kumar in Nail Disorders, 2019
The proximal nail fold is a continuation of the skin of each digit, forming the dorsal surface that folds underneath itself forming the ventral surface and rests above the nail matrix. The dorsal proximal nail fold is devoid of hair follicles, sebaceous glands, and dermatoglyphic markings; however, there is a normal granular layer. The ventral proximal nail fold also lacks rete ridges. The proximal nail keratinizes by formation of cuticle (Eponychium), which is attached to the upper surface of the nail plate. Cuticle acts as a seal to potential space between proximal nail fold and dorsal nail plate and loss of cuticle compromises the protective role of the proximal nail fold and leaves nail matrix vulnerable to external microbes and allergens. Chronic manipulation, manicure, inflammation, and infection can result in loss of cuticle, which heralds the onset of chronic paronychia.2
Ethnic Hair Care Products
Dale H. Johnson in Hair and Hair Care, 2018
Epps and Wolfram have shown that African-American hair is more difficult to comb and requires much higher forces to comb. The excessive grooming of hair causes damage to hair cuticles, as evident from the study conducted by Kelly and Robinson (22). They found that shampooing and towel drying inflect some damage to the cuticles, but wet combing or brushing greatly increases the cuticular damage. It is therefore incumbent upon a formulating chemist to reduce the work required to comb hair in order to minimize wet combing or brushing damage. Therefore, a conditioner formulated for African-American hair must be very rich in quaternary ammonium compounds to facilitate ease of wet combing while minimizing combing or brushing damage. Various emollients like mineral oils or esters such as isopropyl myristate should be incorporated in the formulations to reduce natural dryness of the African-American hair and scalp. Also, moisture binding ingredients like sodium PCA, panthenol, glycerine, and chitosan, etc., should be utilized to enhance moisture contents of naturally dry African-American hair. Formulas 31 and 32 provide hair with one or more of the following functions: ease of wet and dry combing; smooth, seal, and realign damaged areas of the hair shaft; minimize porosity; impart sheen and silky feel to hair; provide some protection against thermal and mechanical damage; moisturize; add volume and body; and eliminate static electricity. These formulations can adsorb more onto the hair if kept on the hair with a plastic cap for 20 to 30 minutes under a warm dryer (23).
Inflammatory dermatoses affecting the nail
Eckart Haneke in Histopathology of the NailOnychopathology, 2017
Psoriasiform acral dermatitis is clinically very similar to psoriasis of the tip of the fingers including the distal nail bed.52 Onycholysis and finally shortening of the nail bed occur.53 The cuticles are very long and cover parts of the nail. Histologically, there is marked spongiosis with lymphocytic exocytosis, parakeratosis, and scale formation.54 No neutrophils are seen in the epithelium and parakeratosis. However, it was also speculated that this condition might be a particular form of acral psoriasis in children.55 The most recent report proposes to call the condition psoriatic acral dermatitis as the condition is now definitely thought to be a particular variant of acral psoriasis.56
Biotin for the treatment of nail disease: what is the evidence?
Published in Journal of Dermatological Treatment, 2018
Shari R. Lipner, Richard K. Scher
Trachyonychia is described as the roughness of the nail plate (35). It can affect any number of nails and each nail can vary in severity. There are both shiny and opaque types (36). The opaque type is generally more severe and with a ‘sandpaper’ like feel and appearance. There is longitudinal ridging and the cuticle is hyperkeratotic. In the shiny type, the nails have small geometric pits forming longitudinal ridges, but retain their shine. The pathogenesis is likely due to severe chronic defective nail matrix keratinization for the opaque type and mild intermittent inflammation in the shiny type’ (37). Trachyonychia is most common in the pediatric population and is associated with psoriasis, lichen planus, and alopecia areata, but most cases are idiopathic (38,39). Treatment options include observation, topical steroids, intralesional matrix kenalog injections, systemic corticosteroids, cyclosporine, and retinoids (40).
A Cross-Sectional Observational Study of Nailfold Capillary Morphology in Uveitis
Published in Current Eye Research, 2018
Xuling Chen, Xuyang Yao, Ying Chi, Chunying Guo, Jing Zhang, Jun Li, Shijie Zhang, Xin Rong, Louis R. Pasquale, Liu Yang
We used a JH-1004 microscope (Jiangsu Jiahau Electronic Instrument Co., Jiangsu, China) set at × 280 magnification to image and video the microvasculature. Subjects were seated at room temperature (20–25°C) for 15–20 minutes to acclimatize and get them relaxed before the test.13 In consideration that nailfold microvasculature can vary from finger to finger, we examined the fourth and fifth digits on each subject’s non-dominant hand. This approach allowed for adequate vascular sampling and minimized effects of microvascular changes introduced by nonmedical conditions.14 The nailfold was located just proximal to the lunula and cuticle,15 (Figure 1a). In order to improve the epidermal translucency and visibility of underlying capillaries, a drop of cedar oil was placed on the nailfold of each finger before observation. The procedure was performed by a doctor masked to the patient’s condition.
Approved and emerging Bruton’s tyrosine kinase inhibitors for the treatment of chronic lymphocytic leukemia
Published in Expert Opinion on Pharmacotherapy, 2022
Alycia Hatashima, Mehdi Karami, Mazyar Shadman
Last, ibrutinib’s off-target toxicities due to EGFR inhibition are thought to cause the diarrhea and dermatologic complications frequently observed with ibrutinib. Diarrhea predominantly occurs within the first 6 months of treatment and is self-limiting in nature with a median duration of 6–20 days. Diarrhea was the most common any grade toxicity at approximately 50% and grade ≥3 diarrhea was reported in 4% and 7% of patients in the RESONATE and RESONATE-2 trials, respectively [15,17]. Rash is also a common manifestation of EGFR inhibition and has been described in up to 27% of ibrutinib-treated patients [51]. While most cases are self-limiting, rare dermatologic toxicities have occurred. Additionally, brittle nails and textural hair changes have been reported and can be symptomatically managed with cuticle oil or biotin supplementation.
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