Hair zinc, scalp hair quantity, and diaper rash in normal infants

Hair zinc concentration was determined by atomic absorption spectrophotometry in 308 normal newborn infants and 199 normal infants aged one to twelve months. Hair zinc concentration declined from 204 micrograms/gm at birth to 112 micrograms/gm at age eight months, and then rose to 144 micrograms/gm at age twelve months. Diaper rash was significantly associated with reduced hair zinc, and infants with the least hair had lower zinc levels than infants with the most hair. The data indicate that hair loss and diaper rash found in normal infants is significantly associated with a reduction in hair zinc concentration.     

Hair pain (trichodynia): frequency and relationship to hair loss and patient gender

BACKGROUND: Patients complaining of hair loss frequently claim that their hair has become painful. OBJECTIVE AND METHODS: The aim of the study was to evaluate the frequency of this phenomenon and its relationship to hair loss. Patients seeking advice for hair loss either spontaneously reported or were questioned about painful sensations of the scalp. Hair loss activity was quantified by a hair pull, daily count and wash test. Telogen percentage was obtained by a hair pluck. The scalp surface was examined by dermatoscopy. RESULTS: Of 403 examined patients, 20% of women and 9% of men reported hair pain, irrespective of the cause and activity of hair loss. A minority presented scalp telangiectasia. This strongly correlated with hair pain. CONCLUSIONS: Hair pain (trichodynia) affects a significant proportion of patients complaining of hair loss and may increase the anxiety. The symptom neither allows discrimination of the cause nor correlates with the activity of hair loss. A higher prevalence of female patients might be connected to gender-related differences in pain perception in relation to anxiety. The role of vasoactive neuropeptides in the interaction between the central nervous system and skin reactivity is discussed. In the absence of any correlation with quantitative parameters of hair loss or specific morphologic changes of the scalp, management remains empiric and tailored to the individual.     

Hair density, hair diameter and the prevalence of female pattern hair loss

BACKGROUND: Female pattern hair loss is common but estimates of its prevalence have varied widely. The relationships between the clinical diagnosis of female pattern hair loss and objective measurements of hair density and hair diameter have not previously been evaluated. OBJECTIVES: To determine the prevalence of female pattern hair loss and to relate the clinical findings to hair density and hair diameter. METHODS: We examined 377 women, aged 18--99 years, who presented to a general dermatology clinic with complaints unrelated to hair growth (the unselected sample). A second group of 47 women referred with typical female pattern hair loss was included in analyses of the relationships between hair density, hair diameter and the clinical diagnosis. Hair density was measured using a photographic method. In each subject the major and minor axis diameters were measured in a random sample of 50 hairs. RESULTS: Six per cent of women aged under 50 years were diagnosed as having female pattern hair loss, increasing to 38% in subjects aged 70 years and over. The mean +/- SEM hair density was 293 +/- 61.3 hairs cm(-2) at age 35 years, falling to 211 +/- 55.1 hairs cm(-2) at age 70 years. Hair density showed a normal distribution in the unselected sample. Most women classified as having female pattern hair loss had hair densities within the lower half of the normal distribution. The perception of hair loss was determined mainly by low hair density (ANOVA P < 0.001), but there was overlap in hair density between women classified as having Ludwig I hair loss and the no hair loss group, which was partly accounted for by differences in mean hair diameter (ANOVA P < 0.001). Low hair density was associated with fewer hairs of all diameters. CONCLUSIONS: Hair density in women is distributed as a normal variable, indicating that it is determined as a multifactorial trait. Women with female pattern hair loss have a hair density which falls below the mean but lies within the spectrum of the normal distribution, although other factors, including hair diameter, may affect the subjective impression of hair loss. The hair diameter data suggest that low hair density is not due to progressive diminution in hair follicle size and that follicular miniaturization may occur within the space of a single hair cycle.     

Hair weathering and hair capacitance mapping: a pilot study

Background Currently, there is no reported objective method allowing confident assessment of hair hydration mapping. Thus, assessing hair moisture kinetics and versatility according to hair shaft damages and hair care products is difficult to perform. Aim To explore a new method for assessing hair moisture. Method A new method of hair capacitance mapping (HCM) is introduced for monitoring hair surface damage and hydration. This study was performed on intact and weathered hair locks. Samples were soaked in 10% solutions of regular shampoos or in tap water alone. HCM was performed using the SkinChip^® device based on a semiconductor image sensor technology. Time to complete water desorption from cuticular cells was recorded. Results Hair surface moisture was increased for <30 min after soaking in the shampoos or water alone. The method was sensitive enough to disclose a gradient of moisture from the base to the tip of the hair shafts. Weathered hairs lost their moisture more rapidly than intact hairs. Conclusion Hair capacitance mapping appears to be a promising method in the assessment of the dynamics of hair surface moisture.     

Functional anatomy of the hair follicle: The Secondary Hair Germ

The secondary hair germ (SHG)—a transitory structure in the lower portion of the mouse telogen hair follicle (HF)—is directly involved in anagen induction and eventual HF regrowth. Some crucial aspects of SHG functioning and ontogenetic relations with other HF parts, however, remain undefined. According to recent evidence (in contrast to previous bulge‐centric views), the SHG is the primary target of anagen‐inducing signalling and a source of both the outer root sheath (ORS) and ascending HF layers during the initial (morphogenetic) anagen subphase. The SHG is comprised of two functionally distinct cell populations. Its lower portion (originating from lower HF cells that survived catagen) forms all ascending HF layers, while the upper SHG (formed by bulge‐derived cells) builds up the ORS. The predetermination of SHG cells to a specific morphogenetic fate contradicts their attribution to the “stem cell” category and supports SHG designation as a “germinative” or a “founder” cell population. The mechanisms of this predetermination driving transition of the SHG from “refractory” to the “competent” state during the telogen remain unknown. Functionally, the SHG serves as a barrier, protecting the quiescent bulge stem cell niche from the extensive follicular papilla/SHG signalling milieu. The formation of the SHG is a prerequisite for efficient “precommitment” of these cells and provides for easier sensing and a faster response to anagen‐inducing signals. In general, the formation of the SHG is an evolutionary adaptation, which allowed the ancestors of modern Muridae to acquire a specific, highly synchronized pattern of hair cycling.     

Hair and nail diseases in the mature patient

The elderly population is growing, lifespans are increasing, and a greater emphasis on geriatric care is being implemented in hospital systems. With a higher percentage of the population living longer, hair and nail diseases associated with the advanced stages of life are becoming more prevalent. Common hair diseases in the elderly include androgenetic alopecia, senile alopecia, frontal fibrosing alopecia, and erosive pustular dermatosis of the scalp. Nail diseases associated with advanced age include onychomycosis, brittle nails, onychocryptosis, onychoclavus, onychogryphosis, subungual hematomas, subungual exostosis, myxoid cysts, and malignancies. These diseases can have a serious impact on a patient’s quality of life. In an effort to familiarize the reader with these common changes and abnormalities, we discuss hair and nail diseases in the mature patient.     

Hair cross-sectioning in uncombable hair syndrome: An epoxy embedding technique

Uncombable hair syndrome is a rare disorder of the hair shaft that leads to silvery and unruly hair. The hair shaft anomaly is characterized by a longitudinal groove that is detected by scanning electronic microscopy—considered to be the gold standard for diagnosis. Recently, hair cross-sectioning has been reported as a viable alternative, but currently available methods still have some flaws, especially because of hair samples' processing specificities. Here, we present two cases of uncombable hair syndrome and a new embedding technique using epoxy to perform the diagnosis.     

Hair colouring, permanent styling and hair structure

Hair is an important component of body image and has immense psychological importance for both men and women. Women, in particular, over the ages have modified their appearance through changing their hair colour or style. Hair can be straight, wavy or curly, blonde, black, brown or red. These natural variations are an important part of our identity that can be manipulated according to the dictates of fashion, culture or society. Different types of hair have varying affinity for the different colouring and waving methods. Damaged hair also has a different affinity for hair products than normal healthy hair. The hair shaft is remarkably strong and resistant to the extremes of nature. Hair cosmetics are widely available and manipulate the structural properties of hair. Whilst most procedures are safe, there is considerable potential for damage to the hair and hair problems of acute onset, including hair breakage, hair loss and loss of condition, are frequently blamed on the last product used on the hair. Hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair.     

Hair dye-sensitized hairdressers: the cross-reaction pattern with new generation hair dyes

Hair dye allergies are a frequent cause of occupational skin disease among hairdressers. Conventional hair dyes contain 4-phenylenediamine (PPD), 2, 5-diaminotoluene sulfate (DTS) and 2-nitro-4-phenylenediamine (ONPPD) as allergens. In new generation hair dyes, FD & C and D & C dyes are used in the hair dye formulations. This study investigated the cross-reaction pattern of new generation hair dyes among hairdressers (n = 40) with a known allergy to PPD and/or DTS and/or ONPPD. In the 40 hairdressers no positive reactions were observed to the single FD & C and D & C dyes. In two hairdressers, doubtful reactions were observed to one or more of the hair dye formulations. The data from this study suggest that for hairdressers sensitized to PPD and/or DTS and/or ONPPD this new generation of hair dyes is a safe alternative for use in their salons.     

Hair on a gene string: recent advances in understanding the molecular genetics of hair loss

The hair follicle is finally, after remaining a mystery for many years, beginning to yield some of its molecular secrets. The past decade has seen unprecedented and ever quickening advances in understanding the molecular genetics of the many single gene disorders, which have alopecia as a major feature. This article reviews recent novel clinical and experimental observations, which have shed new light on the basic molecular mechanisms underlying hair morphogenesis, differentiation, keratinization and cycling. We consider recent progress in understanding structural hair defects and complex traits and consider where future developments are likely to occur.     

Hair cycle-specific expression of versican in human hair follicles

BACKGROUND: Versican, a large chondroitin sulfate proteoglycan molecule, is implicated in the induction of hair morphogenesis, the initiation of hair regeneration, and the maintenance of hair growth in mouse species. In contrast, in human hair follicles, the distribution and the roles of versican remains obscure. OBJECTIVES: To elucidate the implication of versican in normal human hair growth. METHODS: Versican expression was examined by in situ hybridization (mRNA) and immunohistochemistry (protein). RESULTS: The results clearly showed specific versican gene expression in the dermal papilla of anagen, which apparently decreased in the dermal papilla of catagen hair follicles. No specific signal was detectable in telogen hair follicles. Consistent with ISH results, versican immunoreactivity was extended over the dermal papilla of anagen hair follicles, and again, this staining diminished in the catagen phase of human hair follicles. Interestingly, versican proteins were deposited outside K15-positive epithelial cells in the bulge throughout the hair cycle. Versican immunoreactivity in the dermal papilla was almost lost in vellus-like hair follicles affected by male pattern baldness. CONCLUSION: Specific expression of versican in the anagen hair follicles suggests its importance to maintain the normal growing phase of human as well as mouse.