JAMA Dermatology

<jats:p>This Viewpoint discusses different approaches to evaluating and managing melanoma in situ to help mitigate the potential harms of overdiagnosis.</jats:p>

The rapid rise in cutaneous melanoma diagnoses.

N Engl J Med

Melanoma overdiagnosis: why it matters and what can be done about it.

Br J Dermatol

Lived experiences and fear of cancer recurrence among survivors of localized cutaneous melanoma.

JAMA Dermatol

Revision of the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis classification schema for melanocytic lesions: a consensus statement.

JAMA Netw Open

Melanoma over-diagnosis: historical perspective and the path forward.

Dermatol Pract Concept

Impact of dermoscopy and short-term sequential digital dermoscopy imaging for the management of pigmented lesions in primary care: a sequential intervention trial.

A randomised, controlled, multicentre trial of imiquimod versus radiotherapy for lentigo maligna.

J Clin Oncol

This Viewpoint discusses different approaches to evaluating and managing melanoma in situ to help mitigate the potential harms of overdiagnosis.

Navigating Melanoma In Situ in the Age of Overdiagnosis.

Navigating Melanoma In Situ in the Age of Overdiagnosis

<jats:p>This Patient Page describes the symptoms, diagnosis, and treatment of acne keloidalis nuchae.</jats:p>

This Patient Page describes the symptoms, diagnosis, and treatment of acne keloidalis nuchae.

Acne Keloidalis Nuchae.

Acne Keloidalis Nuchae

British Journal of Dermatology

<jats:title>Abstract</jats:title>
               <jats:p>The ability to grow long scalp hair is a distinct human characteristic. It probably originally evolved to aid in cooling the sun-exposed head, although the genetic determinants of long hair are largely unknown. Despite ancestral variations in hair growth, long scalp hair is common to all extant human populations, which suggests its emergence before or concurrently with the emergence of anatomically modern humans (AMHs), approximately 300 000 years ago. Long scalp hair in AMHs was also a trait that was selected because it conveyed essential signals related to an individual’s age, sexual maturity, health and social status. Biologically, hair length is primarily determined by the amount of time that a hair follicle spends in the active growth phase (anagen). While anagen duration is typically tightly regulated in most mammals, the inherent ability of a hair follicle to continuously recruit new dividing progenitors to its base, where hair fibre is generated, theoretically removes limits on maximal anagen duration. We propose a model wherein hair cycle progression into and out of anagen is regulated by evolutionary malleable molecular checkpoints. Several animal species and domesticated animal breeds display long body hair, which suggests that extremely long scalp hair in humans emerged via attenuation of an existing out-of-anagen checkpoint mechanism rather than via a newly evolved molecular programme. Studying congenital and somatic mosaicism conditions featuring altered hair length could potentially unveil the currently unknown molecular basis underlying this human trait.</jats:p>

Taiwan Bio-Development Foundation

Taiwan National Science and Technology Council

National Institutes of Health

A new scenario for the evolutionary origin of hair, feather, and avian scales

J Anat

Functional complexity of hair follicle stem cell niche and therapeutic targeting of niche dysfunction for hair regeneration

J Biomed Sci

A genetic basis of variation in eccrine sweat gland and hair follicle density

Proc Natl Acad Sci USA

The evolution of bipedality and loss of functional body hair in hominids

J Hum Evol

The vestiary hypothesis of human-hair reduction

J Hum Evol

Avoidance of overheating and selection for both hair loss and bipedality in hominins

A naked ape would have fewer parasites

Proc Biol Sci

Human scalp hair as a thermoregulatory adaptation

The role of geography in human adaptation

PLOS Genetics

Exaptation – ‌‌a missing term in the science of form

Paleobiology

Beauty and the beast: mechanisms of sexual selection in humans

Evol Hum Behav

The human hair follicle, a bistable organ?

Exp Dermatol

Human hair cycle

J Invest Dermatol

The hair cycle on the human thigh and upper arm

The role of keratin proteins and their genes in the growth, structure and properties of hair

The nutritional biochemistry of wool and hair follicles

Anim Sci

Morphological changes in human scalp hair roots during deprivation of protein

Science

Hair growth in kwashiorkor

Arch Dis Child

The social and ritual contextualisation of Ancient Egyptian hair and hairstyles from the Protodynastic to the end of the Old Kingdom

The evolution of skin pigmentation and hair texture in people of African ancestry

Dermatol Clin

African hair morphology: macrostructure to ultrastructure

Int J Dermatol

Origins of modern human ancestry

Nature

The earliest modern humans outside Africa

The genetic structure and history of Africans and African Americans

Inference of human population history from individual whole-genome sequences

The women of Brassempouy: a century of research and interpretation

J Archaeol Method Theory

12,000-year-old Aboriginal rock art from the Kimberley region, Western Australia

Sci Adv

Diversity in human hair growth, diameter, colour and shape. An in vivo study on young adults from 24 different ethnic groups observed in the five continents

Eur J Dermatol

Quantitative hair form variation in seven populations

Am J Phys Anthropol

Hundreds of variants clustered in genomic loci and biological pathways affect human height

African hair growth parameters

The nature of Neanderthal introgression revealed by 27,566 Icelandic genomes

The biology and genetics of curly hair

The adaptive variant EDARV370A is associated with straight hair in East Asians

Hum Genet

Seven Chinchorro mummies and the prehistory of northern Chile

Resting no more: re-defining telogen, the maintenance stage of the hair growth cycle

Biol Rev Camb Philos Soc

A guide to studying human hair follicle cycling in vivo

Self-organizing and stochastic behaviors during the regeneration of hair stem cells

Hedgehog signaling reprograms hair follicle niche fibroblasts to a hyper-activated state

Dev Cell

Label-retaining cells reside in the bulge area of pilosebaceous unit: implications for follicular stem cells, hair cycle, and skin carcinogenesis

Cell

Chronobiology of the hair follicle: hunting the “hair cycle clock”

J Investig Dermatol Symp Proc

Morphogenesis and renewal of hair follicles from adult multipotent stem cells

Lower proximal cup and outer root sheath cells regenerate hair bulbs during anagen hair follicle repair after chemotherapeutic injury

Mobilizing transit-amplifying cell-derived ectopic progenitors prevents hair loss from chemotherapy or radiation therapy

Cancer research

Epidermal patterning and induction of different hair types during mouse embryonic development

Birth Defects Res C Embryo Today

Wounding, mortality and mane morphology in African lions, Panthera leo

Anim Behav

Angora mouse mutation: altered hair cycle, follicular dystrophy, phenotypic maintenance of skin grafts, and changes in keratin expression

Vet Pathol

Cell cycle regulation by checkpoints

Methods Mol Biol

FGF5 is a crucial regulator of hair length in humans

Control of murine hair follicle regression (catagen) by TGF-beta1 in vivo

FASEB J

Corticosterone inhibits GAS6 to govern hair follicle stem-cell quiescence

Changes in plasma prolactin and wool follicle growth induced by short to long day transition in New Zealand Wiltshire sheep

J Endocrinology

Prolactin and its receptor are expressed in murine hair follicle epithelium, show hair cycle-dependent expression, and induce catagen

Am J Pathol

Cyclic dermal BMP signalling regulates stem cell activation during hair regeneration

Stress-induced premature senescence of dermal papilla cells compromises hair follicle epithelial-mesenchymal interaction

J Dermatol Sci

FGF5 as a regulator of the hair growth cycle: evidence from targeted and spontaneous mutations

Apoptosis in wool follicles during mouse epidermal growth factor (mEGF)-induced catagen regression

Telogen effluvium: a review of the literature

Cureus

Seasonal changes in human hair growth

Clinical pathobiology of radiotherapy-­induced alopecia: a guide toward more effective prevention and hair follicle repair

Prostaglandin E2 prevents radiotherapy-induced alopecia by attenuating transit amplifying cell apoptosis through promoting G1 arrest

Baldness in nonhuman primates

J Soc Cosmetic Chemists

The evo-devo puzzle of human hair patterning

Evol Biol

Diversity, topographic differentiation, and positional memory in human fibroblasts

Mesenchymal-epithelial interactions in the skin: increased expression of dickkopf1 by palmoplantar fibroblasts inhibits melanocyte growth and differentiation

J Cell Biol

Hox in hair growth and development

Naturwissenschaften

The use of ectopic volar fibroblasts to modify skin identity

Regeneration, repair and remembering identity: the three Rs of Hox gene expression

Trends Cell Biol

Contemporary hair transplantation

Dermatol Surg

Hoxc-dependent mesenchymal niche heterogeneity drives regional hair follicle regeneration

Cell Stem Cell

Dermal papilla cell number specifies hair size, shape and cycling and its reduction causes follicular decline

Development

Epithelial-mesenchymal micro-niches govern stem cell lineage choices

In search of the “hair cycle clock”: a guided tour

Differentiation

Autologous cell-based therapy for male and female pattern hair loss using dermal sheath cup cells: a randomized placebo-controlled double-blinded dose-finding clinical study

J Am Acad Dermatol

Scalable production of controllable dermal papilla spheroids on PVA surfaces and the effects of spheroid size on hair follicle regeneration

Biomaterials

Four independent mutations in the feline fibroblast growth factor 5 gene determine the long-haired phenotype in domestic cats

J Hered

A homozygous missense mutation in the fibroblast growth factor 5 gene is associated with the long-hair trait in Angora rabbits

BMC Genomics

Fgf and Wnt signaling interaction in the mesenchymal niche regulates the murine hair cycle clock

Nat Commun

Short anagen hair syndrome: association with mono- and biallelic variants in WNT10A and a genetic overlap with male pattern hair loss

Signalling by senescent melanocytes hyperactivates hair growth

Localizing recent adaptive evolution in the human genome

PLOS Genet

Modeling recent human evolution in mice by expression of a selected EDAR variant

Single-cell and spatial transcriptomic analysis of human skin delineates intercellular communication and pathogenic cells

Defining transcriptional signatures of human hair follicle cell states

Human hair follicle organ culture: theory, application and perspectives

Hair-bearing human skin generated entirely from pluripotent stem cells

Tracing the peopling of the world through genomics

Divergence-time estimates for hominins provide insight into encephalization and body mass trends in human evolution

Nat Ecol Evol

The Oldowan: the tool making of early hominins and chimpanzees compared

Annu Rev Anthropol

3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya

The ability to grow long scalp hair is a distinct human characteristic. It probably originally evolved to aid in cooling the sun-exposed head, although the genetic determinants of long hair are largely unknown. Despite ancestral variations in hair growth, long scalp hair is common to all extant human populations, which suggests its emergence before or concurrently with the emergence of anatomically modern humans (AMHs), approximately 300 000 years ago. Long scalp hair in AMHs was also a trait that was selected because it conveyed essential signals related to an individual's age, sexual maturity, health and social status. Biologically, hair length is primarily determined by the amount of time that a hair follicle spends in the active growth phase (anagen). While anagen duration is typically tightly regulated in most mammals, the inherent ability of a hair follicle to continuously recruit new dividing progenitors to its base, where hair fibre is generated, theoretically removes limits on maximal anagen duration. We propose a model wherein hair cycle progression into and out of anagen is regulated by evolutionary malleable molecular checkpoints. Several animal species and domesticated animal breeds display long body hair, which suggests that extremely long scalp hair in humans emerged via attenuation of an existing out-of-anagen checkpoint mechanism rather than via a newly evolved molecular programme. Studying congenital and somatic mosaicism conditions featuring altered hair length could potentially unveil the currently unknown molecular basis underlying this human trait.
The ability to grow long hair on the scalp is a distinct human characteristic. Hair on the scalp may have originally evolved to aid with cooling of the head when exposed to the sun. However, the genetic determinants of long hair are unknown. All human populations have had long scalp hair, despite ancestral differences in hair growth. This suggests that long hair originated before or at the same time as the emergence of anatomically modern humans (AMHs), approximately 300,000 years ago. Long scalp hair in AMHs was also selected because it represented important messages related to a person’s age, sexual maturity, health and social status. The amount of time that a hair follicle spends in an active growth phase (called ‘anagen’) is the primary biological factor that determines hair length. While anagen duration is regulated in most mammals, the ability of a hair follicle to continuously recruit new dividing progenitors to its base (where hair fibre is generated) theoretically removes limits on the length of duration. We propose a model where hair cycle progression in and out of the active growth phase is controlled by evolutionary malleable molecular checkpoints. Several animal species and domesticated animal breeds display long body hair. This suggests that extremely long scalp hair in humans emerged via attenuation of an existing out-of-anagen checkpoint mechanism, rather than through a newly evolved molecular programme. Studying mosaicism diseases that feature altered hair length could help to identify the molecular basis for this trait in humans.

Evolution of long scalp hair in humans.

Evolution of long scalp hair in humans

Papers