Childhood malnutrition is associated with a reduction in the total melanin content of scalp hair

Hair microscopy: an easy adjunct to diagnosis of systemic diseases in children

Hair, having distinct stages of growth, is a dynamic component of the integumentary system. Nonetheless, derangement in its structure and growth pattern often provides vital clues for the diagnosis of systemic diseases. Assessment of the hair structure by various microscopy techniques is, hence, a valuable tool for the diagnosis of several systemic and cutaneous disorders. Systemic illnesses like Comel-Netherton syndrome, Griscelli syndrome, Chediak Higashi syndrome, and Menkes disease display pathognomonic findings on hair microscopy which, consequently, provide crucial evidence for disease diagnosis. With minimal training, light microscopy of the hair can easily be performed even by clinicians and other health care providers which can, thus, serve as a useful tool for disease diagnosis at the patient's bedside. This is especially true for resource-constrained settings where access and availability of advanced investigations (like molecular diagnostics) is a major constraint. Despite its immense clinical utility and non-invasive nature, hair microscopy seems to be an underutilized diagnostic modality. Lack of awareness regarding the important findings on hair microscopy may be one of the crucial reasons for its underutilization. Herein, we, therefore, present a comprehensive overview of the available methods for hair microscopy and the pertinent findings that can be observed in various diseases.

Nutrition and hair

Healthy hair results from a combination of good generalized health and mindful health care practices. Many nutritional deficiencies lead to poor hair health and include changes to hair structure, texture, and viability. Although the mechanisms by which individual nutrients contribute to hair growth and maintenance have yet to be fully resolved, there are a variety of risk factors that predispose an individual to a nutritional deficiency; age, malnutrition, malabsorption, and medication use are among the most common. A thorough history should be taken in a patient with a hair disturbance to identify risk factors for a nutritional deficiency, which will then guide directed laboratory testing and treatment.

Climate change, women's workload in smallholder agriculture, and embodied political ecologies of undernutrition in northern Ghana

The burden of child undernutrition across Africa remains extraordinarily high. Among children under age five, chronic and acute undernutrition is responsible for more ill-health than any other cause. While climate change exacerbates the multiple burdens of undernutrition, we know very little about the embodied effects on women's workload in agriculture and implications for feeding practices, especially for infants whose nutrition depends on mothers' time. In this article, political ecologies of health, with its nested, place-based analysis, is used as a framework to address this knowledge gap. The study took place in Ghana's Upper West Region, a semi-arid and resource-poor setting with higher undernutrition rates. In-depth interviews were conducted with smallholder farmers (n = 33) whose infants have sub-optimal growth, and key informants (n = 7) with expertise in nutrition and health. Findings from the study demonstrate how climate change puts pressure on women's productive time, leading to poor child feeding practices and undernutrition. Ultimately, the article argues that there are hidden impacts of climate change on undernutrition. Global undernutrition interventions should therefore move beyond biomedical solutions to address these hidden impacts, some of which are social, gendered, and structural in nature.

Edematous severe acute malnutrition is characterized by hypomethylation of DNA

Edematous severe acute childhood malnutrition (edematous SAM or ESAM), which includes kwashiorkor, presents with more overt multi-organ dysfunction than non-edematous SAM (NESAM). Reduced concentrations and methyl-flux of methionine in 1-carbon metabolism have been reported in acute, but not recovered, ESAM, suggesting downstream DNA methylation changes could be relevant to differences in SAM pathogenesis. Here, we assess genome-wide DNA methylation in buccal cells of 309 SAM children using the 450 K microarray. Relative to NESAM, ESAM is characterized by multiple significantly hypomethylated loci, which is not observed among SAM-recovered adults. Gene expression and methylation show both positive and negative correlation, suggesting a complex transcriptional response to SAM. Hypomethylated loci link to disorders of nutrition and metabolism, including fatty liver and diabetes, and appear to be influenced by genetic variation. Our epigenetic findings provide a potential molecular link to reported aberrant 1-carbon metabolism in ESAM and support consideration of methyl-group supplementation in ESAM.

Systemic causes of hair loss

Hair loss is both a common chief complaint by patients and a clinical challenge for physicians, especially general practitioners, yet few dermatological problems yield as much patient satisfaction when resolved as hair loss. The diagnosis is often attributed to androgen-related hair loss, while other causes, some of which are life-threatening but treatable, are overlooked. We searched for relevant literature on hair loss and supported these findings with our clinical experience to identify seven major systemic etiologies of hair loss, ranging from infectious agents to consumption of unsafe supplements. Many causes are only described in the literature through case studies, though some original articles and meta-analyses are available. Careful history taking, proper examination techniques, and judicious use of laboratory tests are essential to reach at the correct diagnosis in a cost-effective manner when performing patient work-up. Such methodical evaluation of hair loss can result in the appropriate treatment plan and provide significant patient satisfaction. Key messages Hair loss is a common chief complaint and a difficult challenge for both general practitioners and dermatology consultants. We identified seven major categories of systemic hair loss etiology and present a framework for their clinical evaluation. A methodical approach to hair loss can result in the appropriate treatment plan and provide significant patient satisfaction.

Sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (Hirundo rustica)

Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin) in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica), its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown) and belly (white-to-brownish) feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu) differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations, potentially reflecting adaptation to different natural and sexual selection regimes, and that some coloration components seem to be highly heritable.

Nutrition and hair: deficiencies and supplements

Hair follicle cells have a high turnover. A caloric deprivation or deficiency of several components, such as proteins, minerals, essential fatty acids, and vitamins, caused by inborn errors or reduced uptake, can lead to structural abnormalities, pigmentation changes, or hair loss, although exact data are often lacking. The diagnosis is established through a careful history, clinical examination of hair loss activity, and hair quality and confirmed through targeted laboratory tests. Examples of genetic hair disorders caused by reduced nutritional components are zinc deficiency in acrodermatitis enteropathica and copper deficiency in Menkes kinky hair syndrome.

Diversity of human hair pigmentation as studied by chemical analysis of eumelanin and pheomelanin

Hair colour is one of the most conspicuous phenotypes in humans, ranging from black, brown, blond to red. This diversity arises mostly from the quantity and ratio of the black-dark brown eumelanin and the reddish-brown pheomelanin. To study the chemical basis underlying the diversity of hair colour, we have developed several chemical methods to quantify those two pigments. Alkaline H(2) O(2) oxidation affords pyrrole-2,3,5-tricarboxylic acid (PTCA) as a eumelanin marker and thiazole-2,4,5-tricarboxylic acid (TTCA) as a pheomelanin marker. Pheomelanin can also be analysed as 4-amino-3-hydroxyphenylalanine (4-AHP) after hydroiodic acid hydrolysis. Using those methods, we evaluated the contents of eumelanin and pheomelanin (the 'chemical' phenotype) in human hairs of black, dark brown, brown, light brown, blond and red colour (the 'visual' phenotype). Eumelanin contents decrease in that order, with a trace but constant level of pheomelanin, except for red hair which contains about equal levels of pheomelanin and eumelanin. Thus, the chemical phenotype correlates well with the visual phenotype. The genotype of melanocortin-1 receptor (MC1R), a gene regulating the red hair phenotype, is predictive of hair melanin expressed as the log value of eumelanin to pheomelanin ratio, with a dosage effect evident. Hair melanin contents were also analysed in patients with various hypopigmentary disorders including Hermansky-Pudlak syndrome, Menkes disease, proopiomelanocortin deficiency, cystinosis, malnutrition and trace metal deficiency. The chemical phenotype helped evaluate the precise effects of each disease on pigmentation. In studies of human hair, the chemical phenotype will find more and more application as an objective measure of pigmentation.

Nutrition and hair

Healthy-appearing hair is a sign of excellent general health, as well as good hair care practices. Most healthy individuals have adequate nutrients in their diet; however, many people do not have access to good nutrition, and others have medical illnesses that predispose them to nutritional deficiency. This is often reflected in changes of scalp and, at times, body hair. Malnutrition, congenital heart disease, neuromuscular disease, chronic illnesses, malignancy, alcoholism, and advanced age can cause hair to change color, be weakened, or lost. Recognition of the populations at risk for vitamin deficiency is the first step to their detection. Changes in skin and hair can provide clues to the presence of an underlying vitamin deficiency.

Nutrition and nutritional supplementation: Impact on skin health and beauty

Skin acts as a natural barrier between internal and external environments thus plays an important role in vital biological functions such as protection against mechanical/chemical damages, micro-organisms, ultraviolet damage. Nutrition has a critical impact on strengthening skin's capabilities to fight against these multiple aggressions.Nutritional deficiencies are often associated with skin health disorders, while diets can either positively or negatively influence skin condition. More recently, the concept of nutritional supplementation has emerged as a new strategy in the daily practice of dermatology as well as a complementary approach to topical cosmetics in the field of beauty. Focusing on human clinical data, this paper proposes to illustrate the link between skin health and nutrition and to exemplify the beneficial actions of nutritional supplementation in skin health and beauty.