HAIR LOSS GLOSSARY – ALOPECIA

HAIR LOSS GLOSSARY – ALOPECIA – DISEASES AND THE MORE COMMON PATHOLOGIES INVOLVING THE SCALP

Keloid acne: It is characterized by the appearance of swelling of the skin (papules) hard and reddish or brown and sometimes plaques in the back of the scalp in particular at the lower end of the neck. The etiology of the phenomenon is unknown. It is thought to be linked to a factor of genetic predisposition and those who are affected are mostly of African ancestry. It is treated with corticosteroids injections, antibiotics and sometimes surgery. As the lesions occur in the donor area their presence constitutes a contraindication for hair transplantation.

Alopecia: It’s the medical term for hair loss of any type. It can result from illness, functional disorder, or a hereditary predisposition.

Alopecia Areata: An autoimmune condition where the body produces antibodies against its own hair follicles. It is characterized by the sudden appearance of smooth circular patches of bald spots on the scalp, beard, eyelashes, or other parts of the body. Hair transplantation is generally not indicated for this condition and treatment consists of injections with cortisone or other medical therapies. Generally the earlier the onset and the more extensive the hair loss, the worse the prognosis. Other characteristic features include: 1) exclamation point hairs – hairs tapered at the bottom due to the inflammation which causes injury to the hair shaft, 2) hair pigment changes, 3) grid-like nail pitting, 4) positive hair pull test – showing telogen hairs and hairs with tapered broken ends (dystrophic anagen hairs).

Alopecia marginalis: Hair loss primarily at the hairline and temples which is usually caused by continued traction from braids or hair extensions. If the condition persists over a length of time, hair loss may become permanent even when braiding is discontinued. Other causes of fall in men which can be attributed to this disease are hereditary miniaturization of the hair line (not linked to a traumatic event) or the syndrome of follicular degeneration.

Alopecia totalis: A type of alopecia areata that leads to total loss of hair on the scalp.

Alopecia Universalis: A type of alopecia areata that affects both the hair of the scalp and all body hair including eyelashes, eyebrows, the trunk, arms and legs.

Anagen: The growth phase of the hair follicle. Usually it lasts from 2 to 5 years.

Anagen effluvium: Extensive hair shedding that results from damage to the hair follicles. It occurs not long after exposure to the agent that causes it. It is characterized by broken hair shafts and tapered, irregular hair roots. Anagen effluvium is seen with chemotherapy and radiation therapy.

Androgenetic alopecia (AGA): Hair loss due to a genetic predisposition of the follicles to the action of DHT (dihydrotestosterone). It is characterized by the progressive replacement of thick terminal with fine and miniaturized hair that will be lost in a matter of months or a few years. Also termed female pattern baldness, male pattern baldness, hereditary alopecia and simply common baldness.

Catagen: It’s the intermittent stage between the growing (anagen) and resting (telogen) phases of the hair growth cycle. In this transitional phase, the follicle stops producing hair and the base of the hair follicle begins to move upwards through the dermis. This phase typically lasts 2-4 weeks.

Chronic telogen effluvium (CTE): Chronic telogen effluvium is characterized by increased shedding of telogen hairs and diffuse thinning especially at the temples. It affects women age 30-60 and can start abruptly with, or without, an initiating factor. It usually does not lead to complete baldness and can resolve in 6 months to 6 years. It typically has a long, fluctuating course with patients losing up to 50-400 hairs/day. Patients with CTE complain of excessive hair shedding whereas those with androgenetic alopecia complain of gradual thinning. The mechanism of CTE is felt to be a shorted anagen (growth) cycle. Unlike androgenetic alopecia, chronic telogen effluvium is not characterized by miniaturized hair follicles. Hair transplants are not indicated in CTE as the hair loss tends to be diffuse and patients should get better over time without treatment.

Density: It’s the number of hairs in a specific area. The average hair density on the scalp is 2.25 hairs/per follicular unit, and and an average of 60-80 follicular units/cm2 in subjects not suffering from baldness. In some persons the scalp density can reach up 120 follicular units/cm2, also depending on the area of the scalp.

Densitometry: Densitometry is a technique that helps assess whether a patient is or is not a candidate for a hair transplant and to predict the future fall. It is based on the analysis of the scalp with instruments capable of providing a high magnification and produce information on the density of the scalp, the number of follicular units present in different areas of the scalp, follicular unit composition and their degree of miniaturization.

Diffuse Patterned Alopecia (DPA): The Diffuse Patterned Alopecia (DPA) is a type of hair loss is characterized by diffuse thinning in the front, top and vertex of the scalp. It is usually associated with a stable permanent zone.

Diffuse Unpatterned Alopecia (DUPA): A type of androgenetic hair loss that occurs over the entire scalp so that there is no permanent zone of hair, normally present in the back and sides of the scalp. The progression of hair loss is often rapid and can result in an almost transparent look due to the low density. Diagnosing DUPA is imperative, as most patients with diffuse unpatterned alopecia should not have a surgical hair restoration, as the transplanted hair will not be permanent. DUPA is a pattern more commonly seen in women. The use of densitometry is very helpful in diagnosing this condition.
Dihydrotestosterone (DHT): DHT is a male hormone that is suggested to be the main cause for the miniaturization of the hair follicle and for hair loss. DHT is formed when the male hormone testosterone interacts with the enzyme 5-alpha reductase.

Discoid lupus erythematosus: It is an autoimmune disorder characterized by scaly red plaques with telangiectasia (presence of very fine blood vessels), plugged follicles, atrophy (thinning of the skin) and pigmentatry changes. The discoid lupus erythematosus often leads to local areas of scarring and permanent localized alopecia.

Treatment involves the use of topical and systemic corticosteroids, anti-malarials, topical tacrolimus, topical imiquimod, isotretinoin, and thalidomide. Hair transplant surgery is not recommended for people who suffer from lupus erythematosus, since the disease process had the propensity to recur. Lupus erythematosus discoid can or can not be associated with the most common systemic lupus erythematosus.

Female Pattern hair loss: Female pattern hair loss is characterized by a gradual miniaturization of the frontal zone and / or top of the scalp with retention of the hairline. Although the most affected areas are the top of the scalp, the process tends to be diffuse, involving the entire scalp in some degree. In female alopecia the genetic explanation seems to be more complex than a simple response to androgens. Women who suffer from female alopecia are candidates for a hair transplant only if the back and sides of the scalp are stable and not affected by thinning.

The various stages of female alopecia are described by the Ludwig scale.

Follicular Degeneration Syndrome: It’s a form of scarring alopecia caused by the premature shedding of the inner root sheath of the hair follicle. This leads in time to the complete destruction of the follicle. Given that often occurs in an area around the front of the scalp we have come to think that the disease was due to traction. Now I think it is a form of idiopathic alopecia (ie, not due to external causes) and there is no correlation to mechanical trauma, or it can be caused by a hot comb.

Folliculitis Decalvans: It’s a form of scarring alopecia characterized by redness, swelling and pustules around the hair follicle, leading to the destruction of the follicle and the consequent permanent hair loss. Folliculitis decalvans affects both men and women and can occur either during adolescence or at any time in adulthood. The exact causes that cause it are unknown. In most cases it has been possible to isolate the bacterium Staphylococcus aureus from pustules, but the role played by this bacterium is not known.

Treatment includes: oral antibiotics, cephalosporin, minocycline, rifampin.

Frontal fibrosing alopecia: More common in post-menopausal women, the front part of the scalp appears shiny, smooth and devoid of hair follicles. This pattern can mimic androgenetic alopecia but, on close inspection one notes scarring and the absence of hair follicle openings. There may be signs of inflammation including redness and scaling. The condition may be a variant of Lichen Planopilaris.

Lichen planopilaris (LPP): It ‘s a disease that affects the hair follicles and that is manifested by scaly reddish area that in turn produce scar tissue and hair loss in areas that are affected. It is characterized by the presence of a band of inflamed cells in the upper level of the dermis that damage the hair follicles.
The treatments include the use of potent topical corticosteroids, corticosteroids for systemic use, antimalarials, cyclosporine for oral use and retinoids.

Loose Anagen Hair Syndrome: This is a very rare condition but seen more often in females than males, presenting early in childhood, usually between the ages of 2 and 9 as diffuse patches of hair loss. This syndrome is characterized by a defective inner root sheath (abnormal keratinization) that prevents it from grasping the hair shaft cuticle. As a result the newly growing hair shaft falls out. The hair is usually blonde, feels matted or sticky, lusterless and does not require cutting. A hair-pull test is positive for anagen hairs. No systemic abnormality is associated with it. With adolescence the hair grows longer, denser and darker, but the hair pull remains positive.

Ludwig scale: Classification of female pattern hair loss. It encompasses three stages: Mild (type 1), Moderate (type II) and Extensive (type III). In all three stages, there is loss on the front and top of the scalp with preservation of the frontal hairline. If the person’s donor hair is stable at the back and sides of the scalp, women of all three types of Ludwig Classification may be candidates for hair transplantation.

Male pattern baldness: Often called androgenic alopecia or common baldness. This is the most common type of hair loss caused by the effects of DHT on the hair follicles susceptible to it. It primarily affects the frontal area, the upper and the vertex and in the higher degrees leaves the person who suffers from it with only a strip of hair available for transplantation at the back of the head and in the form of a horseshoe.

Norwood scale: Published by Dr.O’tar Norwood in 1975 is the best-known classification to describe the genetics of hair loss in humans. The classic Norwood scale consists of 7 stages starting with the recession at the temples and thinning of the crown. The Norwood Class A pattern has five stages and is characterized by a predominantly front to back progression of hair loss.

Pseudo Pelade of Braque: It’s a non-specific scarring alopecia of unknown cause. It also may represent the end stage of other inflammatory scalp conditions. It presents with white or flesh-colored atrophic plaques, without active inflammation.

Systemic lupus erythematosus: It’s an auto-immune disease, where the immune system attacks the body’s own cells, resulting in inflammation and tissue destruction. SLE can affect any part of the body, but most commonly affects the skin, joints, kidneys, heart and blood vessels. The course of the disease is unpredictable, with periods of flares and remissions. Lupus can occur at any age and is more common in women. The skin manifestations are quite varied and can present with localized lesions (DLE), diffuse hair loss and sensitivity to the sun. The name comes from the fact that the photo-sensitive rash that occurs on the face resembles that of a wolf.

Telogen: It is the resting phase of the follicle (lasts 2-4 months). During this period a new hair begins to grow and the old hair is gradually pushed out of the follicle and shed.

Telogen effluvium: This condition has its onset 2-3 months after stress or insult to the scalp. Generally 35-50% of hair is affected. One can see over 300 hairs shed per day. The hairs are characteristically “club” hairs, i.e. telogen hairs that have a small bulb at the end. Telogen effluvium is much more common in women than men.

Tinea capitis (ringworm): It’s a fungal infection of the hair follicles of the scalp, characterized by the formation of small crusts at the base of the follicles. It is also referred to as ringworm of the scalp. It can result in small patches of permanent hair loss. It can be diagnosed by a scalp scraping and a hair pull tested for fungus on a KOH prep and a fungal culture. The most common organism producing this condition is Tinea Tonsurans.

Triangular alopecia: It is characterized by A triangular shaped area devoid of hair that most commonly occurs in the temples. The apex of the triangle often points towards the vertex of the scalp. It can be unilateral or bilateral. Fine, vellus hairs can be seen in the bald patch. The condition appears at birth or in early childhood and is stable. The early, stable appearance, fine vellus hair and characteristic location, help to differentiate it from alopecia areata. Hair transplantation is the treatment of choice.

Traction Alopecia: It develops from continuous traction or pulling on the hair. The hair loss is most prominent at the frontal hairline and temples. It can be seen with hair systems and corn-row hair styles. It is common in African-Americans that braid or corn-row their hair. When long-standing, the hair loss can be permanent.

Trichotillomania: It’s a compulsive disorder that makes a person to pull his or her hair. The most common area is scalp hair causing patchy areas of hair loss with broken hairs of varying lengths. Most commonly seen in females ages 6 to 30. This condition can also involve the eyebrows or upper eyelashes (upper lashes are easier to grab). The diagnosis can be made by cutting or shaving the hair so that it is too short to grab and then observing the growth. Patients suspected of having trichotillomania should be sent for a psychiatric evaluation. A hair transplant is not indicated.

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