Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. It often results in a few bald spots on the scalp, each about the size of a coin. Psychological stress and illness are possible factors in bringing on alopecia areata in individuals at risk, but in most cases there is no obvious trigger. People are generally otherwise healthy. In a few cases, all the hair on the scalp is lost, or all body hair is lost. Hair loss can be permanent, or temporary. It is distinct from pattern hair loss, which is common among males.
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring is not usually present. Hair loss in some people causes psychological distress.
Minoxidil is a medication used for the treatment of high blood pressure and pattern hair loss. It is an antihypertensive vasodilator. It is available as a generic medication by prescription in oral tablet form and over the counter as a topical liquid or foam.
The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between hormones, neuropeptides, and immune cells. This complex interaction induces the hair follicle to produce different types of hair as seen on different parts of the body. For example, terminal hairs grow on the scalp and lanugo hairs are seen covering the bodies of fetuses in the uterus and in some newborn babies. The process of hair growth occurs in distinct sequential stages: anagen is the active growth phase, catagen is the regression of the hair follicle phase, telogen is the resting stage, exogen is the active shedding of hair phase and kenogen is the phase between the empty hair follicle and the growth of new hair.
Alopecia universalis(AU), also known as alopecia areata universalis, is a medical condition involving the loss of all body hair, including eyebrows, eyelashes, chest hair, armpit hair, and pubic hair. It is the most severe form of alopecia areata. People with the disease are usually healthy and have no other symptoms and a normal life expectancy.
The management of hair loss, includes prevention and treatment of alopecia, baldness, and hair thinning, and regrowth of hair.
Alopecia totalis is the loss of all hair on the head and face. Its causes are unclear, but believed to be autoimmune. Research suggests there may be a genetic component linked to developing alopecia totalis; the presence of DRB1*0401 and DQB1*0301, both of which are human leukocyte antigens (HLA), were found to be associated with long-standing alopecia totalis.
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.
Pattern hair loss (also known as androgenetic alopecia (AGA)) 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.
Ophiasis is a form of alopecia areata characterized by the loss of hair in the shape of a wave at the circumference of the head.
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.
Anagen effluvium is the pathologic loss of anagen or growth-phase hairs. Classically, it is caused by radiation therapy to the head and systemic chemotherapy, especially with alkylating agents.
Loose anagen syndrome, also known as loose anagen hair syndrome, is a hair disorder related to dermatology. It is characterised by the easy and pain free detachment of anagen staged hairs from the scalp. This hair condition can be spontaneous or genetically inherited.
Scarring hair loss, also known as cicatricial alopecia, is the loss of hair which is accompanied with scarring. This is in contrast to non scarring hair loss.
Non scarring hair loss, also known as noncicatricial alopecia is the loss of hair without any scarring being present. There is typically little inflammation and irritation, but hair loss is significant. This is in contrast to scarring hair loss during which hair follicles are replaced with scar tissue as a result of inflammation. Hair loss may be spread throughout the scalp (diffuse) or at certain spots (focal). The loss may be sudden or gradual with accompanying stress.
Trichoscopy is a method of hair and scalp evaluation and is used for diagnosing hair and scalp diseases. The method is based on dermoscopy. In trichoscopy hair and scalp structures may be visualized at many-fold magnification. Currently magnifications ranging from 10-fold to 70-fold are most popular in research and clinical practice.
Antonella Tosti is an Italian physician and scientist with major contributions in the field of dermatology, including developing dermoscopy for the diagnosis and care of hair diseases. Her contributions to knowledge about nails include research about videodermoscopy of the hyponychium and the nail plate.
The growth of human hair occurs everywhere on the body except for the soles of the feet, the inside of the mouth, the lips, the backs of the ears, the palms of the hands, some external genital areas, the navel, scar tissue, and, apart from eyelashes, the eyelids. Hair is a stratified squamous keratinized epithelium made of multi-layered flat cells whose rope-like filaments provide structure and strength to the hair shaft. The protein called keratin makes up hair and stimulates hair growth. Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogen. Each phase has specific characteristics that determine the length of the hair.
Prepubertal hypertrichosis, also known as childhood hypertrichosis, is a cutaneous condition characterized by increased hair growth, found in otherwise healthy infants and children. Prepubertal hypertrichosis is a cosmetic condition and does not affect any other health aspect. Individuals with this condition may suffer with low self esteem and mental health issues due to societal perceptions of what a "normal" appearance should be. The mechanism of prepubertal hypertrichosis is unclear, but causes may include genetics, systemic illnesses, or medications.
Minoxidil sulfate, also known as minoxidil sulfate ester or minoxidil N-O-sulfate, is an active metabolite of minoxidil and is the active form of this agent. Minoxidil acts as a prodrug of minoxidil sulfate. Minoxidil sulfate is formed from minoxidil via sulfotransferase enzymes, with the predominant enzyme responsible, at least in hair follicles, being SULT1A1. Minoxidil sulfate acts as a potassium channel opener, among other actions, and has vasodilating, hypotensive, and trichogenic or hypertrichotic effects. Its mechanism of action in terms of hair growth is still unknown, although multiple potential mechanisms have been implicated.
