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Alopecia ( hair loss )

Hair loss- alopecia basics Telogen effluvium. A common presentation in primary care this chart on alopecia on A4Medicine presents the clinician with a structured approach to hair loss.

ANAGEN ( Growth )
 Growth phase Resumption of mitotic activity in the hair bulb and dermal papilla Hair length is dependent on the length of anagen Hair grows at an average 1 cm/28 days Scalp hair has the longest anagen phase lasts 3-7 yrs Approximately 90-95 % of scalp hairs are in an active growing phase at any time Hair is large and has pigment

CATAGEN ( involution )
 Dynamic transition between anagen and telogen Regression phase- signals end of anagen No hair growth- cell death in follicular keratinocytes- club hair Less than 1 % scalp hairs in this 2-3 weeks transitional phase Hair moves closer to epidermis and takes the form of a club hair
TELOGEN ( shedding )
 Resting phase- all activity ceases On scalp- lasts for 2-3 months before anagen 5-10 % of scalp hairs are in teolgen phase Hair can be considered dead will fall out and pushed out by new growing hair Approx 25-100 telogen hairs shed/day ( ↑ on days hair is shampooed ) Normal to shed up to 100 hairs / day
Onset duration and progression Hair thinning or shredding Pattern -Focal or diffuse Any symptoms- itching pain burning Medical and Drug history Stressors / Serious illness – particularly within last 3-6 months Psychosocial history Family history Cosmetics/Hair care products useLocalised versus generalised Scarring or non scarring Inflammatory / Non-inflammatory Follicular plugging PULL test – tests proportion of hairs in telogen
○ grasp 20-30 hairs firmly between thumb index and middle finger
○ slide your fingers along the hair shaft while applying gentle traction
○ positive if > 6 hairs pulled away- suggests active shedding Daily counts Any other associated skin disease
Telogen effluvium→ FBC , Ferritin and TFT
Hair pull test with microscopic evaluation
 Prolactin , FSH , Testosterone , DHEAS , Testosterone-estradiol binding globulin 
 Endocrine study if irregular menses , infertility , hirsuitism , severe acne , galactorrhea or virilization
 Tests to r/o fungal infection ( KOH , Wood light , fungal culture )
 Microscopic examination of hair
 Syphilis ( can mimic alopecia areata )
 Scalp biopsy ( scarring alopecia )
Based on pathophysiology it can be Scarring or Non-scarring Pattern of loss can be Diffuse or Local Can also be classified as disorders of hair shaft and all other forms of hair loss
non scarring –No clinically visible inflammation Atrophy absent Tufting absent Preserved follicular openings.Androgenic alopecia 
( Male and Female pattern ) Alopecia areata Telogen effluvium Anagen effluvium Fungal infections as Tinea capitis → can cause scarring or non scarring alopecia.
Fungal infections
○ eg Tineal capitis- can cause scarring or non scarring alopecia Bacterial infections eg folliculitis Trchotillomania ( hair pulling ) Hypo and hyperthyroidism Hypopituitarism Malnutrition Chronic iron deficiency
androgenic alopecia -male Most common pattern Familial (inheritance not clear , possibly polygenic ) Androgen dependent trait Hair loss 1st from temporal ( triangular pattern ) then vertex Parietal and occiptal regions do not depend on androgens for growth→ so not affected Onset and progression gradual Hamilton classification   Female type Strong genetic predisposition Chronic , diffuse progressive hair loss No loss of frontal hairline No ↑ shedding Ludwig and Christmas tree pattern Women with hyperandrogenism features ( eg acne , hirsuitism and irregular periods ) may need further investigations Some women may have ↑ levels of DHEA-S
Alopecia areata –Well defined circular patches of complete hairloss with no signs of inflammation Probably an autoimmune disorder
( further assesment can be considered ) Common in young adults on scalp or the beard region Exclamation hairs- short broken hairs , yellow dots Associated with other autoimmune diseases as thyroid disorder and vitiligo Patches may be single or multiple Ocassionally patients may loose all / almost all scalp hairs → Alopecia totalis or all body ( alopecia universalis ) Even in mild cases the condition will last many months
Anagen effluvium-Direct effect of anticancer treatment Direct effect of chemotherapy/ radiotherapy on the hair follicles 
( impaired mitotic or metabolic activity ) Tapered fracture of hair shaft ↑ common in combination chemotherapy than with the use of a single drug Regrowth happens when therapy stopped ( unless very high doses used ) usually within 3-6 months

 Eyelashes , Eyebrows , Scalp hair may all be lost- other body hairs less affected
Telogen effluvium-Higher proportion of hair changing from anagen to telogen phase It is a reactive process Hair pull test – strongly positive Women more prone to ↑ed shedding of telogen hairs ↑ ed number of hairs in hairbrush or shower or sometimes thinning of hair in scalp , axillary or pubic hairs Self correcting usually within 6 months 1/3 rd cases no cause found No area of total alopecia and no scarring
Acute → happens 2-3 mts after a triggerring event

○ pyrexia ( 39.1 / 102.5 or more )
○ child bearing
○ major surgery
○ weight loss
○ medication related
 May unmask or aggrevate androgenic alopecia
 Chronic TE- ↑ hair shedding lasting for > 6 months 
♦ idiopathic often self limiting condition
♦ affects middle age women. Other causes -Other causes
 Thyroid dysfunction Profound iron deficiency
( controversial ) Medications Crash dieting Zinc deficiency Secondary syphilis Chronic debilitating illness eg malignancy , malabsorption , hepatic and renal disorders , SLE , dermatomyositis

Scarring alopecia –Injury to hair follicle → permanent destruction of hair follicle Inflammation 2ary to disease Hair follicle replaced by scar tissue Skin may be thick and hypo or hyperpigmented or thin ( epidermal atrophy ) Hair loss is permanent.Lichen planus Chronic cutaneous discoid lupus erythematosus Scarring 2ary to severe bacterial , viral , fungal infection , dissecting cellulitis , acne keloidalis , trauma , follicular mucinosis , tumours , surgical scars Based on biopsy can be Lymphocytic , Neutrophilic or Mixed


British Association of Dermatology leaflet on Alopecia Areata
National Alopecia Areata Foundation
Alopecia UK
British Association of Skin Camouflage -authority on para-medical skin camouflage
An excellent link for patients in the USA
American Hair Research Society on alopecia areata
Pediatric Alopecia areata
Hair loss in cancer treatment from Cancer Net
Telogen Effluvium– some links
Alopecia UK
American Hair Research Society
Female pattern hair loss leaflet from BAD—female-pattern/?showmore=1&
Topical minoxidil patient information from National Skin Centre
Oral minoxidil for hair loss
Excellent work from PCDS
Dermnetz on Telogen Effluvium
BAD Guidelines for the management of Alopecia Areata
Images for reference from The Institute of Trichologists
American Family Physician – Hair loss common causes and treatment
Female pattern hair loss from NermNet NZ
Australian Journal of General Practice on Female pattern hair loss
References ; Further reading

  1. Comprehensive Overview and Treatment Update on Hair Loss Katlein France et al Journal of Cosmetics , Dermatological Sciences and Applications , 2013,3,1-8
  2. Clinical Dermatology – Thomas P.Habif British Association of Dermatologists’ guidelines for the management of alopecia areata 2012 A.G.Messenger et al British Journal of Dermatology
  3. Hair Anatomy and Physiology accessed via
  4. Evaluation and diagnosis of the hair loss patient Thamer Mubki MD et al Journal of the American Academy of Dermatology , 2014-09-01 , Volume 71 , Issue 3 , Pages 415.e 15
  5. Alopecia – an overview Primary Care Dermatology Society Nov 2012 accessed via
  6. Anagen Effluvium Robert A Scwartz et al accessed via
  7. Diseases of Hairs and Nails Antonella Tosti Goldman-Cecil Medicine ,442 , 2703-2701.e2
  8. Telogen Effluvium : A review via
  9. Dermnetz
  10. Harries M JSun JPaus RKing L EManagement of alopecia areata doi:10.1136/bmj.c3671



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