hair
loss, effluvium, alopecia, baldness
androgenic alopecia, androgenetic alopecia, alopecia areata, cicatricial alopecia
 |
|
|
Hair loss is a normal process (45 to 60 hairs/day), the hair that falls out is continuously replaced by newly grown hair.
We lose more hair towards the end of summer and in spring. Hair loss of more than 60 hairs/day is considered abnormal.
Hair loss has very diverse causes.
Diffuse hair loss is mostly encountered in common baldness
(male-pattern and female-pattern alopecia) or telogen effluvium (high fever, pregnancy, medication or severe diet). Anagen
effluvium causes rapid hair loss after cancer chemotherapy or during alopecia areata. Genetic hair loss can be observed in
newborns but mostly appears during childhood (monilethrix, loose anagen hair syndrome, ectodermal dysplasia).
Localized hair loss occurs in male-pattern androgenetic alopecia (in various patterns), fungal infections (tinea), alopecia
areata, cicatricial alopecia (lupus erythematosus, lichen plano pilaris, folliculitis decalvans, central centrifugal cicatricial
alopecia, postmenopausal frontal fibrosing alopecia, etc.) or can be due to traction alopecia (trichotillomania, braiding
and hair straightening). Tumours and skin outgrowths also induce localized baldness (sebaceous nevus, basal cell carcinoma,
squamous cell carcinoma).
Stress has often been pointed at as causing hair loss but this has never
been confirmed by scientific studies. However, anyone can experience stress and its role should not be neglected when faced
with a sizeable hair loss in the weeks following an intense emotional upheaval.
Effective treatment
of hair loss is based on finding the cause of the disorder.
• Telogen effluvium can be
induced by an iron or vitamin B12 deficiency or a thyroid gland disorder which need to be treated. However, it often resolves
spontaneously within 3 or 4 months (after pregnancy, fever, surgery, etc.). In the case of medication-induced telogen effluvium
(isotretinoin, cholesterol-lowering drugs, anticoagulants), the causative treatment must be discontinued and replaced with
an alternative whenever possible.
• Chemotherapy-induced anagen effluvium can be somewhat
minimized by the use of preventive measures (cooling caps).
• Skin diseases and systemic
disorders leading to hair loss must be treated in the appropriate manner and according to each case. Tinea infections require
oral antifungal therapy. Topical, intralesional or systemic corticosteroids are indicated in the treatment of lichen, synthetic
antimalarials (Plaquenil) can also sometimes be useful. Cicatricial alopecia is difficult to treat and requires the intervention
a scalp specialist. Once the pathologic process has been stabilized, hair transplantation can sometimes be considered.
• Hair transplantation or a hairpiece can sometimes be helpful in congenital alopecia.
• Alopecia areata in small patches often resolves quickly without treatment (although there may be relapses),
whereas more severe alopecia areata must be treated as soon as possible with topical (lotion), intralesional (scalp injections)
or more rarely systemic corticosteroids. PUVAtherapy, dithranol (anthralin) and immunotherapy with diphencyprone are often
useful.
• Male-pattern androgenetic alopecia improves with finasteride (Propecia®)
and minoxidil 5%; dutasteride is still being tested in this indication and only temporary results are available. Hair transplantation
remains the sole means of recovering natural hair, the current follicular unit transplant techniques give excellent results
when performed by specialist teams. Female-pattern androgenetic alopecia is a common condition, its treatment includes minoxidil
2% and antiandrogens (cyproterone acetate) in case of obvious hyerandrogenism; finasteride is not currently approved in women,
it is however being tested in postmenopausal women.
| DIFFUSE HAIR LOSS | Children |
Women | Men |
Fast or progressive | • Congenital alopecia
• Hair dysplasia
• Telogen effluvium | • Androgenetic alopecia
• Telogen effluvium |
• Androgenetic alopecia
• Telogen effluvium |
Brutal |
• Chemotherapy
• Alopecia areata
| • Chemotherapy
• Alopecia areata
|
• Chemotherapy
• Alopecia areata
|
LOCALIZED HAIR LOSS
| Children |
Women | Men |
From birth | • Benign congenital alopecia
• Neonatal occipital alopecia
| • Congenital
alopecia | • Congenital alopecia |
Progressive |
• Hair dysplasia |
• Endocrine disorder
| • Androgenetic
alopecia |
Brutal |
• Alopecia areata
• Radiotherapy | • Alopecia areata
• Radiotherapy |
• Alopecia
areata
• Radiotherapy |
Hair breakage | • Tinea infection
• Trichotillomania
• Hair dressing and hair care | • Trichotillomania
• Hair dressing and hair care |
|
Scalp involvement | • Tinea infection
• Cicatricial
alopecia
| • Cicatricial alopecia | • Cicatricial alopecia |
|
|
|
Male-pattern baldness | Female-pattern baldness | Female-pattern baldness |
Alopecia areata-patchy pattern | Alopecia areata-ophiasis pattern | Alopecia areata
totalis pattern |
Cicatricial alopecia from braids | Central
centrifugal cicatricial
alopecia | Pseudopelade of Brocq |
Lichen planopilaris | Frontal
fibrosing alopecia | Lupus erythematosus |
|
|
|
Anagen:
The anagen or growth phase of the hair cycle involves 80 to 90% of the hair and lasts from 2 to 6 years (3 years/1000 days
in men and 5 years in women). The duration of this phase determines the final length of the hair, which grows at a speed of
0.4 mm/day (i.e. 1 cm/month).
Anagen effluvium:>Abnormal hair loss during the anagen or
growth phase. Anagen effluvium is the least common type of hair loss and mostly occurs following a course of medication interfering
with the hair formation process (e.g. chemotherapy), or in alopecia areata.
Androgenetic alopecia
(AGA):>Male or female-pattern androgenetic alopecia is also known as common baldness or androgenogenetic alopecia.
This type of hair loss is due to aging and is characterized in males by progressive balding of the crown of the head and the
forehead, whereas in women hair loss mostly affects the crown. Nevertheless, diffuse hair loss can also occur in male-pattern
androgenetic alopecia whereas female-pattern alopecia can sometimes induce hair loss on the sides of the forehead.
Catagen:>The catagen phase is the intermediate or "resting" phase of the hair cycle,
lasting for 3 weeks and involving 0 to 2% of the hair mass. This phase is intermediate between the anagen or growth phase
and the telogen “shedding” phase of the hair cycle.
Cicatricial alopecia:>Permanent
hair loss; can be due to congenital malformation (congenital aplasia, angioma), trauma (wound, burn or surgery), scalp disease
(lupus erythematosus, lichen planus) or scalp tumour (basal cell carcinoma, squamous cell carcinoma) leading to the formation
of abnormal scar-like tissue.
Congenital:>Present at birth.
Diffuse
alopecia:>Overall decrease in hair density.
Exogen:>The exogen phase is a
subphase of the telogen phase, during which the hair falls out. Roughly 1% of the hair in the telogen phase falls out every
day.
Hair dysplasia:>Abnormality of hair structure.
Hair cycle:>The
different stages of evolution of human hair. The anagen or growth phase involves 80 to 90% of the hair and lasts for 2 to
6 years. During the catagen phase the hair stops growing; this phase lasts for 2 to 3 weeks and involves 0 to 2% of the hair
mass. Lastly, the telogen or shedding phase involves 10 to 20% of the hair and lasts for about 2 to 3 months, after which
the cycle starts again. All abnormal hair loss is characterized by an alteration in the hair cycle pattern.
|
|
|
From Price VH, Treatment of Hair Loss. Review Article. N Eng J Med 1999; 341:964-973 |
|
|
Hair follicle: All the elements forming a hair. Hair follicles are made
up of a hair shaft (the hair itself) and a sebaceous gland and arrector pili muscle attached to it. Hair follicles are grouped
together in follicular units containing 1 to 4 hair shafts.
Localized
alopecia: Localized decrease in hair density.
Normal hair loss: Hair shedding is a continuous and normal process. Normal hair
loss is characterized by the shedding of 45 to 60 hairs a day, it reaches its climax at the end of summer and in spring.
Scalp:> Skin covering the skull and
containing hair follicles.
Telogen:
The telogen phase of the hair cycle is characterized by the involution and shedding of the hair, it involves 10 to 20% of
the hair and lasts for around 3 months (100 days). Roughly 1% of the hair in the telogen phase of the cycle fall out each
day (exogen phase).
Telogen effluvium:> The growing
or involuting hair is rushed into shedding (exogen phase) or the growing hair is rushed into involution followed by shedding.
Telogen effluvium can occur a few weeks after childbirth, surgery, high fever or certain medical treatments, it is also encountered
during attacks of androgenetic alopecia.
Tinea:
Tinea or ringworm is an infection of the hair or facial hair (sycosis) due to dermatophytic fungi.
Traction test:> Test during which the health practitioner
pulls out gently but firmly on a strand of 25 to 30 hairs. The shedding of more than 5 hairs is considered abnormal.
Trichogram: Diagnostic test aiming at quantifying
hair loss, establishing which type of hair loss is present (telogen or anagen effluvium) in order to refer the patient or
to diagnose their condition. A strand of hair is taken from the forehead, temples and neck using tweezers. The hair is examined
microscopically and classified according to its type (anagen, catagen, telogen). The rate of shrinking of the hair can also
be assessed, as well as the occurrence of dystrophic bulbs, which are found in alopecia areata or anagen effluvium.
Trichotillomania: Irrepressible need of
pulling or twisting one's hair leading to hair breakage and hair loss. This tic is considered as being part of obsessive compulsive
disorder (OCD).
|
|
|
Patient Support Groups
• National Alopecia Areata Foundation - A non profit organization dedicated to providing information about alopecia areata. With support groups in the USA and
contacts with similar support groups worldwide.
• Delaware Valley Alopecia Support Group - Support and ideas for those with the condition of alopecia areata, alopecia totalis, and alopecia universalis.
