• The term comes from “alopex” (renard) because the annual hair loss of this animal
  • Alopecia is a scarcity or a temporary or permanent disappearance, localized or diffuse the hairiness

Épidémiologie :

  • very frequent reason for consultation affects both men and women
  • Button mostly adults, is more severe in children
  • The forms most frequently encountered are : alopecia areata and androgenic alopecia

alopecia 1Reminder anatomical :

  • Normal hair has between 100.000 and 160.000 hair
  • The average density is 250 at 300 hairs per cm2
  • 30 at 80 Hair is renewed day, a drop of more than 100 hair day is pathological
  • A seasonal accent of the fall is noted in autumn
  • Follicle pilose : is a thin envelope & rsquo; s epidermis & rsquo; is dug into the dermis, to house the hair root, at 4 mm under the scalp
  • Taste buds : through which the blood arrives
  • Matrix : which generates the keratin cells and transforms them into hair
  • Gaines epithelial : serving as tutor to the hair shaft formation
  • Cycle pilaris : All hair are born, live and die all over again and this is called the hair cycle

Phase anagen : growth phase, it corresponds to a keratinocyte proliferation phase of the matrix keratins, the expensive 3 at 7 years and determines the length of hair that grows on average 1 cm per month, longer in women

Phase  catagen :  the involution phase is a phase of regression, it corresponds to the involution of hair follicles by cell death of keratinocytes with shortening of the epithelial stem and follicle upward movement. This phase is very fleeting and lasts 15 days

Phase telogen : resting phase, is a change in depth,  trichocytes reactive germinal form a new structure

Phase exogenously : phase hair fall, enzymatic phenomena release fasteners of the old telogen hair shaft and the hair will come offalopecia 2

CAT in front of a alopecia

Diagnostic etiological :

  • Examination : it must identify the following : start date, intensity, Contributing factors (stress, drug intake, exposure to toxic, cosmetic habits ...), Medical-Surgical personal history, family history, treatment already undertaken and results. These elements will evoke :

Effluvium telogen : recent fall, Quick and disseminates

Alopecia incorporated : progressive imperceptible

Alopecia related at a affection dermatological

Alopecia related at a affection General : hormonal, Infectious ...

  • Exam clinique :

Physique :   suffering from mucocutaneous first or nail,   signs of nutritional deficiencies (Iron deficiency or trace elements),   Clinical signs of general pathology (dysthyroïdie, hirsutisme, acne, cycle disorders)

Exam of alopecic areas : locating alopecic areas

Aspect of please haired : I got, squameux, pustular, inflammatory or scar

alopecia 3Aspect  of the  hair :  pilar dysplasia (hereditary alopecia),  broken hair (trichotillomanie), tensile strength, the presence of small hair, hair duvets, brittle hair

Importance the fall : Tensile test

  • exams Additional : they are rarely necessary and are necessarily oriented examination and clinical.

specific :

Trichogramme : 50 hair is depilated using a clamp, it is carried out in three zones (front, vertex and occipital low), ensuite, the roots are examined microscopically. This review confirms the absence of hair dystrophy, it can reassure the patient when the hair loss is physiological. It allows to specify the mechanism of the fall (Anagen effluvium or telogen effluvium), calculates the ratio telogen / anagen (increased during exacerbations of androgenic alopecia (Aag))

Exam mycological (Wood light)

Exam bacteriological

Exam Hair optical polarized light microscopy : highlights a hair dysplasia

Biopsy cutaneous + immunofluorescence direct : cicatricial alopecia or tumor

Balance Sheets  biological :  NFS (deficiency…),  dosing of trace elements (zinc,  suffers ...),  hormone assays : thyroid (TSH, T3, T4), testosterone, DHEA, progesterone (looking for adrenal hyperandrogenism), D4 androstenedione (looking for Ovarian hyperandrogenism), hepatic and renal balance (Research shortcomings)

main types of alopecia :

  • alopecia diffuses :

Effluvium telogen :

Definition : scarcity diffuse hair, Leather healthy scalp, Positive pull test,

acute or subacute phenomenon, predominates the temples and near the ears

factors triggers  (2-3 month) : delivery,  abortion, prolonged fever (infectious or other),  acute hemorrhage,  sudden weight loss,  stress,  emotional shock ...

Evolution : spontaneous regrowth in 4 at 6 months or even a year

Conduct at have : reassurance, ask for laboratory tests if the fall is very important or persistent,  twice-daily applications for 2 to 3 months of Minoxidil 2% or 5% with risk of increasing the effluvium from treatment

alopecia 4alopecia iatrogènes :

toxic : pesticides, arsenic…

drug : antimitotic

alopecia linked at a pathology General : dysthyroïdies, systemic diseases like connective, lymphomas, vasculitis ...

alopecia infectious : parasitic (malaria), viral (zone), bacterial ...

alopecia androgénétiques : the androgenetic alopecia terms explains the dual origin of this phenomenon :  responsiveness to male hormones hair roots,  genetic predestination hair to undergo this stimulation

Epidemiology :

Men : they reach one in three men at 30 years near & rsquo; one in two men in 50 years

Women : about 70 % women face hair fall problem during a period of their lives but they are generally favored a hormonally until menopause or pre menopause

alopecia 5▪ The Di-Hydro Testosterone (DHT)  at the pilosebaceous follicle induces a reduction of the anagen phase, growth inhibition and involution of the dermal papilla,  miniaturization of the pilosebaceous follicle capillary. DHT has an opposite action : the hair ècroissance / the hair èinvolution

▪ The image of alopecia as Hamilton and recently Norwood is classified, where women observe a maintenance of the occipital areas

▪ Androgenetic alopecia image defined by Ludwig in three stages (I, II, III) or maintenance of the free will be noted

alopecia 6In the topics from sex male : first observed a decline temporoparietal forming gulfs and a frontal baldness and baldness occipito-vertical. The areas initially keep some hair intermediate and downs, which can then disappear completely. Hamilton, Norwood then identified the developmental stages usually followed by male pattern baldness

alopecia 7In  the  topics  from  sex  feminine  :  the anteroposterior change is less marked than in men. Alopecia is more diffuse and draws a cap that complies with a narrow anterior frontal band,   ainsi que les régions et temporales occipitales. Intermediate hair and duvets are involved in many terminal hair. Ludwig described three grades, of increasing severity, between which there are no objective limits

▪ Search biological hyperandrogenism to androgenetic alopecia :

❖ Needless humans

❖ No need to set a good woman having no acne or hirsutism

❖ useless if small signs of hyperandrogenism in peri-menopause

❖ Between the third and sixth day of the cycle, Remote taken any hormonal

In unscrambling : testosterone, delta-4-androstènedione

Suspicion adrenal origin : test the immediate Synactènet (17-OH-P et 21 deoxy-cortisol)

Suspicion original ovarian : scan (trans-vaginal), prolactin, FSH, LH

Conduct at have :

✓ Minoxidil 2% or 5%, 2 applications / day for months.

Man : Finasteride (inhibitor of 5α-reductase) : 1 mg / day for 2 years.

Women :

Treatment antiandrogens : cyproterone acetate (androcur) : 25-

50 mg / day, 1st to 21st day of the cycle (hirsutisme)

oestroprogestatif : 1er-day 21 : Diane 35

treatments surgical : reserved for patients whose baldness stabilized

car Greffes : mini- and micro-grafting +++

  • alopecia 8alopecia localized :

Non-scarring :

Slade : it affects 2% Population, of unknown etiology, genetic predisposition, environmental factors,   infectious factors,   emotional stress,  neurological factors (association with vitiligo,  thyroiditis ...),  it occurs in a subject in good condition and a healthy scalp.

✓ Alopecia isolated plaques or multiple, can be generalized (pelade decalvans)  even reach all hairy areas (pelade universalis).

✓ Nail involvement is possible (micro-abrasions, longitudinal grooves)

Evolution : unpredictable : healthy regrowth in months (white down that pigmented later), extension, recidivism

Conduct at have :

shapes  limited : topical application of corticosteroids by injection, application locale de Minoxidil 2% or 5%

shapes diffuses : corticosteroid intralesional injection, dermocorticoïdes,  corticosteroids bolus (Recent extensive alopecia areata),   immunotherapy contact (PUVA), Methotrexate ± corticosteroids : 25 mg / week, from 9 at 18 month.

❖ In some cases (diffuse forms or recurrent) : psychological support is necessary

alopecia 9alopecia infectious :


impetigo and folliculite : scalp pustular, inflammatory, hair tufts, satellite lesions,   bacterial removal, antibiotic treatment

scar :

▪ They are characterized clinically by :  atrophy of the scalp,  disappearance of the pores corresponding to the destroyed follicles.

▪ They result from an inflammatory condition where the hair follicle is either the direct target (lichen plan pilaire, cutaneous lupus, folliculite décalvante…) either nonspecifically destroyed (sarcoïdose, scleroderma, Trauma ...)

▪ Destruction by an inflammatory infiltrate in the region infundibular region where there is the stem cells that could regenerate damaged follicle

alopecia 10Alopecia from traction : unlike the female AGA, traction alopecia achieved readily temples and the front anterior edge. On areas of progression, there are broken hair short and not duvets. The headgear, very pulled back bun, knotted tight braids,  after straightening curly hair,  Natural hair can,  by continuous traction, lead to the destruction of some follicles

Lichen plan follicular : middle-aged woman, Many plates atrophic expansive coalescent, perifollicular erythema purplish, follicular hyperkeratosis. Lichen skin surface or mucous rarely associated (17-28%)

Alopecia fibrosing front Postmenopausal (fibrosing alopecia Pinkus) : a very special clinical form of lichen follicular map, described only in postmenopausal women. front reached and temples,   symmetrical and headband,   erythema and follicular hyperkeratosis edge during periods of activity

alopecia congenital : skin atrophy, scalp scar

▪ The etiological treatment, where feasible and effective, helps stop the progression of alopecia, if it is and becomes scar, notes that not surgery

Conclusion :

  • Alopecia is a common reason for consultation, There are many causes : hormonal, nutritional, infectious, drug, etc.
  • Androgenic alopecia and alopecia areata are the most common
  • The telogen effluvium physiological, clinical diagnosis, often requires neither treatment nor explorations.
  • At the & rsquo; child, mycological examination must be systematic.
  • The explorations are not systematic.
  • Treatments, numerous, are more or less effective.