|
DISEASES OF THE HAIR
|
|
|
|
Monilthrex Monilethrix is a hereditary disease characterized by: Sparse scalp hair. Fusiform or spindle swelling of the hair Dryness and fragility of the hair . Pilitorti (twisted hair) : Affects mainly children and is characterized by : Spiral hair Deformed hair shaft with thickened and thin areas . Trichorerhexis nodosa White nodes are arranged irregularly on the hair shaft . Fracture of the shaft at the sites of the nodes. Bamboo hair The hair shaft shows nodes in the form of balls at the distal part of the shaft and sockets at the proximal part of the shaft . Ring hair The hair appears segmented by light and dark color . Kinking hair Twisting and kinking of the hair shaft .
Fig. 426 b Abnormalities of hair growth Pili multigemini Multiple hairs emerging from the same follicle with a common outer root sheath. Trichomycosis axillaris Small nodules of different colors on the hair shaft affecting the axilla and pubic areas in adults.
Folliculitis is an inflammation of the hair follicles that may be due to bacterial or fungal infections. Folliculitis may be superficial or deep . Superficial folliculitis : small pustules surrounded by an erythematous zone develop near the follicular orifice . Deep folliculitis: Small pustules connected by a narrow channel with a deep abscess. Deep folliculitis may leave scarring after healing . Infection is usually caused by Staphylococci predisposed by severe itching and excoriation of skin and mild trauma.
Sites affected are mainly the back of the neck and shoulders. Clinical Features Erythematous macules and follicular papules become generalized appear in a short time accompanied with mild constitutional symptoms such as fever.The follicular papules may resemble keratosis piliaris .
Kyrle‘s
disease Clinical Manifestations This is characterised by follicular hyperkeratosis , which forms a horny corn ,leaving a pit when removed . Sites mainly affected are the lower limbs . Coalescence of the follicular papules may form different shapes such as circinate or verrucous lesions. Atrophic scars may be seen after healing of lesions . Lichen spinulosus This disease affects chiefly children. Minute filiform horny spines that protrude from the follicular openings. Grouped lesions, symmetrically distributed over the trunk, limbs, buttocks, neck, popliteal and extensor surfaces of the arms.
Hair color is primarily under close genetic factors. Enzyme degradation products of melanosomes within matrix cells may cross cell membranes to melanocytes and control further melanin production. Follicular melanocytes are known to respond like epidermal melanocytes to melanocyte stimulating hormone (MSH), which can darken light-colored hair. Premature graying of hair has been defined as the onset of hair graying before 20 years of age in Caucasoid and 30 years of age in Negroid. It probably has a genetic basis and occasionally occurs as an isolated autosomal dominant condition. Etiology
Syndromes associated with piebaldism Tiez’s syndrome Generalized ‘white spot‘. Loss of skin and hair pigment. Complete deaf mutism. Waardenburg‘s syndrome The Vogt-Koyanagi-Harada syndrome. This syndrome is characterized by: Alopecia areata. Bilateral uveitis. Labyrinthine deafness. Tinitus, vitiligo and poliosis Alezzandrini‘s syndrome Unilateral facial vitiligo. Retinitis. Poliosis of eyebrows and eyelashes . Perceptive deafness is rarely associated. Tuberose sclerosis Depigmented hair may be the earliest sign . Von Recklinghausen‘s disease Multiple neuro fibromatosis: café au lait macules, axillary, perineal freckling, and cystic lesions. Nutritional deficiencies In protein malnutrition, such as in kwashiorkor, hair color changes which are prominent features. Normal black hair becomes brown or reddish, and brown hair becomes blonde. Severe iron-deficiency anemia. White hair may occur in vitamin B12 deficiency. Metabolic disorders Severe ulcerative colitis and after extensive bowel resection. Phenylketonuria :Black hair may become brown., Homocystinuria. Accidental hair discoloration Exposure to high concentrates of copper in industry or from inadvertently high concentrations in tap water or in swimming pools may cause green hair, particularly visible in blonde-haired subjects. Picric acid and Dithranol may cause yellowish hair. Hair cosmetics Soaps and shampoos are made from vegetable or animal fats that can remove dirt and greases as efficiently as detergents . The ingredients contained in the shampoos such as tar and many others may cause change of the hair color. Straightening gels and fixatives of the hair may have also the same effect.
The term "hirsutism" and "hypertrichosis" includes excessive hair growth of any type in any distribution. Newborn infants may have pigmented hair covering the skin surface, which usually shed after few weeks. This may be related to increased circulating androgens from the mother. Etiology Idiopathic: This type is of unknown origin that can affect any age even small children and babies. In idiopathic hirsutism the concentration of plasma testosterone is usually within or only slightly above the normal range; androstenedione is more often found to be elevated . The sensitivity of androgen receptors in the skin may be increased to androgen and this is believed to be the cause of hirsutism in presence of normal circulating androgens.
Endocrinopathic hirsutism Abnormality of the pituitary, adrenal and ovarian glands may produce hirsutism. Cushing‘s syndrome and Stein Leventhal syndrome are associated with hirsutism. The growth of facial, trunk and extremity hair in the male and of pubic and axillary hair in both sexes is clearly dependent on androgens. Testosterone from the interstitial cells of the testis is responsible for growth of beard and body hair in male adolescence. Scalp hair differs in that its growth does not require any androgenic stimulus. Increased androgens on the other hand may cause falling and recession of hair in post pubertal males. Most female diffuse alopecia is androgenic. While it may be associated with virilism and high androgen levels resulting from disorders of the adrenal cortex or ovaries, plasma androgens are usually normal. Genetic hirsutism Congenital anomalies such as congenital hypertrichosis and Cornelia de Lange syndrome. Hirsutism may appear early in children and young age. Congenital hirsutism. This type is inherited and transmitted as an autosomal dominant, where vellus hair may cover the entire skin surface except the palms and soles, which are free of hair follicles. Congenital hypertrichosis is associated in some areas besides hirsutism with dental anomalies and gingival fibromatoses. Emotional factors : Stress has been blamed to cause hirsutism . Psychic trauma and emotional stress in spite that it may cause falling of hair, it may cause hirsutism in susceptible individuals. This may be related to the increased 17 ketosteroids in emotionally disturbed persons. Familial :Some types of idiopathic hirsutism are familial running in families and certain races especially dark skinned individuals. Starvation: may cause hirsutism Metabolic disorders: such, as error of metabolism of porphyrins may be associated with hirsutism. Naevi such as giant and Becker‘s nevus may be associated with localized hirsutism. Drugs Different drugs such as ACTH, corticosteroids, hexachlorobenzene, Diphenylhydantoin and testosterone may induce hirsutism. The response to testosterone depends on the testosterone receptors in the skin and their sensitivity to the amount given.
SYNDROMES ASSOCIATED WITH HIRSUITISM Stein-Leventhal syndrome Clinical Manifestations
Adrenogenital syndrome Clinical Features
Cushing‘s syndrome In this syndrome the vellus hair becomes more pigmented . Diabetes bearded women syndrome This syndrome usually appears in diabetic females. Clinical Features
Cornelia de lange syndrome Clinical manifestations:
Treatment of Hirsutism Treatment of the cause . Wax depilation: The oriental ladies use an old traditional preparation of lemon and sugar heated forming a paste which is applied to the hairy extremities or other parts then this paste after some times is pulled from the skin surface. This preparation is widely used and can get red of hair and an easy and less expensive method. Disadvantages: Painful especially if applied to sensitive areas of the body. In spite that this can give a very clean skin surface from hairs, it leaves ecchymotic areas, which after healing may leave some pigmentation. Leaves in growing hair under the skin surface and papular rough surface . Shaving of the hair: This is also a simple method .It can give good satisfactory results especially if shaving is applied from up and down and not to reverse the direction of shaving where this may lead to coarse, thick more pigmented hair after regrowth. Laser hair depilation : Different types of lasers are available recently which cause destruction of hair follicles and can get rId of unwanted hair on the chin and the body . This method is safe , effective but is more expensive.
|
-reductase
type I and II, aromatase, and androgen receptor in hair
follicles of women and men with androgenetic alopecia. J
Invest Dermatol 1997; 109: 296-300
| Contents | << Previous Chapter | Next Chapter >> | Search |