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Nutritional Diseases
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Chelsea Kesty, Madeline Hooper, Erin McClure, Emily Chea, Cynthia Bartus
Clinical presentation: Patients with anorexia may present with lanugo-like hairs, especially on the face and arms. Patients with bulimia may exhibit Russel’s sign, which are calluses or scars on the dorsal hands from repeated self-induced vomiting (Figure 31.3). Such patients also may have hypertrophic salivary glands and erosion of the tooth enamel.
Hair and hairy scalp
Published in Richard Ashton, Barbara Leppard, Differential Diagnosis in Dermatology, 2021
Richard Ashton, Barbara Leppard
Three types of hair occur in humans: Lanugo hair is the soft silky hair that covers the foetus in utero. It is usually shed before birth.Vellus hair is the short fine unpigmented hair which covers the whole skin surface apart from the palms and soles.Terminal hair is longer, coarser, and pigmented. Before puberty, terminal hair is restricted to the scalp, eyebrows and eyelashes. After puberty, secondary terminal hair develops in response to androgens on the beard area, in the axillae, pubic area and on the front of the chest in men.
The skin
Published in Frank J. Dye, Human Life Before Birth, 2019
Although hair begins to develop in the 12th week of development, it is not until the 20th week that it becomes readily visible. Hair first appears on the head and then progresses toward the tail end of the fetus. The first hair to appear is lanugo, a fine, downlike hair confined to the fetal period (see Figure 9.7). Gradually, lanugo is replaced by hair more typical of babies. As the hair develops, sebaceous glands appear near the bases of the hair shafts (see Figure 12.1). The secretions of these glands (sebum), the periderm cells, and the lanugo together make up a whitish, cheesy coat on the skin of the fetus, called vernix caseosa (Figure 12.4). This protective layer prevents what would otherwise be harmful effects of amniotic fluid on the delicate skin of the fetus. Each hair has an associated smooth muscle fiber, which, unlike the ectodermally derived hair shaft and sebaceous gland, is derived from the dermis. These arrector pili muscles cause us to have a “hair-raising” experience under certain stressful conditions (see Figure 12.1).
Advancements in the repair of large upper eyelid defects: A 10-year review
Published in Orbit, 2021
Erin Jennings, Mark Krakauer, William R. Nunery, Vinay Kumar Aakalu
Grafts, regardless of source, require a vascularized anterior lamella for viability. In large, full-thickness defects often there is little remaining upper lid tissue, thus techniques require locoregional, vascularized flaps from the adjacent tissue that simulates the thin, pliable, tissue of the normal upper eyelid. Previously described techniques include the unipedicled (Fricke) flap, bipedicled flaps, paramedian forehead flaps, the Tessier nasojugal flap, an islandized superficial temporal artery flap, and the lower to upper eyelid transposition flap.2 These flaps can be bulky and may result in the need for pedicle division or thinning of the mobilized tissue. In addition, the tissue composing these flaps rarely meet the unique functionality required of the upper lid. Lastly, lanugo hairs can pose a risk of corneal irritation and result in aesthetic outcomes that are unfavorable.
An evaluation of the available pharmacotherapy for the treatment of hirsutism
Published in Expert Opinion on Pharmacotherapy, 2023
Leila Asfour, Ahmed Kazmi, Rodney Sinclair
Body hair follows the same growth cycle as scalp hair, including the three phases: anagen, which is the growth phase; catagen, which is the involution/regressing phase and finally telogen, which is the resting phase [13]. There are three types of hair: lanugo hair, which is soft, not pigmented, and sheds sometime late in gestation or early postpartum; vellus hairs, which are short, fine, light‐colored, and barely noticeable, but cover most parts of the body; and terminal hairs, which are thicker, longer, and pigmented, and can be found on the scalp, the axillae, the genital region, eyebrows, and eyelashes [14].
Malignant proliferating trichilemmal tumor of the scalp: report of 4 cases and a short review of the literature
Published in Case Reports in Plastic Surgery and Hand Surgery, 2022
Cemal Alper Kemaloğlu, Melikgazi Öztürk, Beyza Aydın, Özlem Canöz, Orhun Eğilmez
On the other hand, MPTT is a less often adnexial cancer originating from the outer sheath epithelium of hair follicles. MPTTs constitute less than 0.1% of skin cancers [10]. Although it usually develops over existing pilar cysts, they can also occur as a denovo without a precursor lesion [11]. They are generally seen on the sun-exposed areas and especially on the scalp in elderly women. Since it originates only from the terminal hair root, it is very unlikely to develop from lanugo in bald men or from nonterminal hair follicles on the body [12].