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 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]
Human hair color is the pigmentation of human hair follicles and shafts due to two types of melanin: eumelanin and pheomelanin. Generally, the more melanin present, the darker the hair. Its tone depends on the ratio of black or brown eumelanin to yellow or red pheomelanin. Melanin levels can vary over time, causing a person's hair color to change, and one person can have hair follicles of more than one color. Some hair colors are associated with some ethnic groups because of the observed higher frequency of particular hair colors within their geographical region, e.g. straight, dark hair amongst East Asians, Southeast Asians, Polynesians, some Central Asians, and Native Americans; a large variety of dark, fair, curly, straight, wavy or bushy amongst Europeans, West Asians, some Central Asians, and North Africans; and curly, dark, and uniquely helical hair amongst Sub Saharan Africans. Bright red hair is found in some European populations, and hair turns gray, white, or "silver" 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.
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.
Poliosis circumscripta, commonly referred to as a "white forelock," is a condition characterized by localized patches of white hair due to a reduction or absence of melanin in hair follicles. Although traditionally associated with the scalp, poliosis can affect any hairy area on the body, including eyebrows, eyelashes, and beards. Microscopically, poliosis is marked by the lack of melanin or melanocytes in the hair bulbs, though epidermal melanocytes typically remain unaffected unless associated with conditions like vitiligo.
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.
The medical condition 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.
Giant solitary trichoepithelioma is a cutaneous condition characterized by a skin lesion that may be up to several centimetres in diameter.
A pilar sheath acanthoma is a cutaneous condition most often found on the face, particularly above the upper lip in adults. Pilar sheath acanthoma is a skin-colored, 5-10 mm diameter papule or nodule with a keratin-filled pore in the center. Pilar sheath acanthoma diagnosis confirmed by shave or excisional biopsy. Successful treatment requires surgical excision.
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.
Nevoid hypertrichosis is a cutaneous condition characterized by the growth of terminal hairs in a circumscribed area. Nevoid hypertrichosis often presents shortly after birth. The cause of nevoid hypertrichosis is unknown. The diagnosis is made based of clinical and histopathological examination.
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.
{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)