Premature greying of hair (PGH), also known as canities, is the process of greying of hair occurring at an unusually early age. It can have negative effects on appearance, self-confidence, self-esteem, and social acceptance of the affected individual. Hair is said to have greyed prematurely if it occurs before the age of 20 years in Europeans, before 25 years in Asians, and before 30 years in Africans. [1]
Cause of greying is incompletely understood. It is a complex multi-factorial process mainly considered to be an interplay of nutritional, genetic and environmental factors.
Stress causing over-activation of the sympathetic nervous system increases noradrenaline release in hair follicles. This overproduction causes depletion of the melanocyte stem cells which are required to produce melanin, the pigment responsible for hair color. [2]
Premature greying of hair has been observed with greater frequency among certain families, suggesting a familial predisposition for the condition. As hair pigmentation is a result of complex interaction between various genetic factors, it is thought that premature greying could be due to exhaustion of melanocyte's capability to produce hair pigmentation. [1] Premature canities may occur alone as an autosomal dominant condition or in association with various autoimmune or premature aging syndromes. Down syndrome (trisomy 21) is characterized by features of accelerated aging including premature greying of hair and deficient DNA repair. [3] Premature greying needs to be differentiated from various genetic hypomelanotic hair disorders.
Smoking is another factor that is considered to be related to premature greying of hair. Smoking results in generation of huge amount of reactive oxygen species leading to increased oxidative stress culminating into damage to melanin producing cells, melanocytes. [4] [5] Prolonged exposure to ultraviolet rays is considered to initiate similar processes in hair follicles resulting in premature greying of hair.
Nutritional deficiencies: [6] [7] [8]
If the cause is due to melanocyte stem cell interruption during the growth cycles due to stress or illness then the use of photobiomodulation for cellular rejuvenation may reverse the process. [9]
Topical anti-aging compounds that are currently under investigation include photo protectors, such as cinnamidopropyltrimonium chloride and solid lipid nanoparticles as carriers for UV blockers, oral supplementation with l-cystine and l-methionine, and topical melatonin. [5]
Melanin consist of oligomers or polymers arranged in a manner which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. They have been described as "among the last remaining biological frontiers with the unknown".
Human hair color is the pigmentation of human hair follicles due to two types of melanin: eumelanin and pheomelanin. Generally, if more melanin is present, the color of the hair is darker; if less melanin is present, the hair is lighter. The tone of the hair is dependent on the ratio of black or brown eumelanin to yellow or red pheomelanin. Levels of melanin can vary over time causing a person's hair color to change, and it is possible to have hair follicles of more than one color on the same person. Some hair colors are associated with some ethnic groups due to observed higher frequency of particular hair color within their geographical region, e.g. straight dark hair amongst East Asians, Southeast Asians, Polynesians, Central Asians and Native Americans, a large variety of dark, fair, curly, straight, wavy and bushy hair amongst Europeans, West Asians, Central Asians and North Africans, curly, dark, and uniquely helical hair with Sub Saharan Africans, whilst gray, white or "silver" hair is often associated with age.
Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin.
Trichology is the study of the hair and scalp. The term derives from Ancient Greek θρίξ (thríx), "hair" and -λογία -logia. In most jurisdictions the title of a trichologist, not the field of trichology, is considered a para-medical discipline.
Trichobacteriosis axillaris is a superficial bacterial colonization of the hair shafts in sweat gland–bearing areas, such as the armpits and the groin. It is a trivial disease of worldwide occurrence that is believed to be caused by the genus Corynebacteria.
Pattern hair loss is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front hairline, loss of hair on the crown (vertex) of the scalp, or a combination of both. Female-pattern hair loss (FPHL) typically presents as a diffuse thinning of the hair across the entire scalp.
White piedra is a mycosis of the hair caused by several species of fungi in the genus Trichosporon. It is characterized by soft nodules composed of yeast cells and arthroconidia that encompass hair shafts.
Greying of hair, also known as greying, canities, or achromotrichia, is the progressive loss of pigmentation in the hair, eventually turning the hair grey or white which typically occurs naturally as people age.
Pili torti is characterized by short and brittle hairs that appear flattened and twisted when viewed through a microscope.
Madarosis is a condition that results in the loss of eyelashes, and sometimes eyebrows. The term "madarosis" is derived from the ancient Greek "madaros", meaning "bald". It originally was a disease of only losing eyelashes but it currently is the loss of both eyelashes and eyebrows. Eyebrows and eyelashes are both important in the prevention of bacteria and other foreign objects from entering the eye. A majority of patients with madarosis have leprosy, and it was reported that 76% of patients with varying types of leprosy had madarosis.
Pseudopelade of Brocq is a flesh- to pink-colored, irregularly shaped alopecia that may begin in a moth-eaten pattern with eventual coalescence into larger patches of alopecia.
Pressure alopecia, also known as postoperative alopecia, and pressure-induced alopecia, occurs in adults after prolonged pressure on the scalp during general anesthesia, with the head fixed in one position, and may also occur in chronically ill persons after prolonged bed rest in one position that causes persistent pressure on one part of the scalp, all likely due to pressure-induced ischemia.
Hair casts, also known as pseudonits, represent remnants of the inner root sheath, and often occur in great numbers and may mimic nits in the scalp.
Trichostasis spinulosa is a common but rarely diagnosed disorder of the hair follicles that clinically gives the impression of blackheads, but the follicles are filled with funnel-shaped, horny plugs that are bundles of vellus hairs.
Graham-Little syndrome or Graham Little-Piccardi-Lassueur syndrome is a cutaneous condition characterized by lichen planus-like skin lesions. It is named after Ernest Graham-Little.
Oral pigmentation is asymptomatic and does not usually cause any alteration to the texture or thickness of the affected area. The colour can be uniform or speckled and can appear solitary or as multiple lesions. Depending on the site, depth, and quantity of pigment, the appearance can vary considerably.
Canities subita, also called Marie Antoinette syndrome or Thomas More syndrome, is an alleged condition of hair turning white overnight due to stress or trauma. The trivial names come from specific cases in history including that of Queen Marie Antoinette of France whose hair was noted as having turned stark white overnight after her capture following the ill-fated flight to Varennes during the French Revolution. An older case of Sir Thomas More's hair turning white the night before his beheading has also been recorded. Although a number of cases of rapid hair greying have been documented, the underlying patho-physiological changes have not been sufficiently studied.
Trichomegaly is a condition in which the eyelashes are abnormally long, objectively defined as 12mm or greater in the central area and 8mm in the peripheral. The term was first used by H. Gray in 1944 in a publication in the Stanford Medical Bulletin, though he was only the third person to characterize the disorder; the first two reports were published in German in 1926 and 1931 by Reiter and Bab, respectively. Gray suggested the use of the term "movie lashes" to describe this condition, for long lashes were at the time being portrayed in film as a desirable characteristic in women.
Frictional alopecia is the loss of hair that is caused by rubbing of the hair, follicles, or skin around the follicle. The most typical example of this is the loss of ankle hair among people who wear socks constantly for years. The hair may not grow back even years after the source of friction has ended.
Desmond John Tobin is an Irish academic, researcher and author. He is a Full Professor of Dermatological Science at University College Dublin and the Director of the Charles Institute of Dermatology. He was Chair of British Society for Investigative Dermatology from 2018 to 2020. Tobin is a fellow of The Royal College of Pathologists, of the Higher Education Academy, of the Royal Society of Biology, Institute of Biomedical Science, and of the Institute of Trichologists.
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