Hair loss Flashcards
What is alopecia areata?
An autoimmune condition leading to hair loss
What is the epidemiology of alopecia areata?
Starts in childhood in 50%, 80% by the age of 40yrs
Lifetime risk 1-2%, ethnicity and sex independent
FHx present (including other autoimmune conditions e.g. thyroid disease, vitiligo, atopic eczema) in 10-25%
What causes alopecia areata?
T-cell infiltration around hair follicles
Onset or recurrence of hair loss sometimes triggered by:
- Viral infection
- Trauma
- Hormonal changes
- Emotional/physical stressors
How does alopecia areata present?
Mostly asymptomatic aside from a bald patch noticed incidentally e.g. by a hairdresser
Sometimes there is burning, prickling, discomfort in hair loss areas = trichodynia
Hair loss affects:
- Scalp
- Eyebrows
- Eye lashes
- Beard
3 Stages:
- Sudden loss of hair
- Enlargement of bald patch/es
- Regrowth of hair
Exclamation mark hairs:
- 2-3mm, broken or tapered with a club shaped root
- Microscopy shows a thin proximal shaft and normal calibre distal shaft
Regrowth:
- Initially grey/white, may even be curly
- Months-years of regrowth
- Patches can form in the regrowth
How quickly can people lose hair in alopecia?
From weeks to years
If a certain amount of hair has gone after a year, with no regrowth then the chances of proper regrowth is slim but there are no consistent predictors of regrowth (i.e. can be hairless for years then spontaneously regrow)
What is: Alopecia totalis? Alopecia universalis? Ophiasis? Diffuse alopecia areata? Alopecia areata of the nails?
Totalis:
- 5% of patients with autoimmune hair loss
- All/nearly all of scalp hair is lost
Universalis:
- Affects <1% of cases
- All/nearly all hair of whole body is lost
Ophiasis:
- Alopecia affecting occipital and lateral scalp
Diffuse:
- Persisting hair turns grey/’turning white overnight’
- Positive hair pull test
Nails:
- 10-50% of those with areata
- Pitting and ridging of nails +/- koilonychia, Beau lines, onycholysis etc
What are some complications of alopecia areata?
May be temporary or persistent
Severe + persistent = increased chances of psychological consequences
Should be assessed for atopy, vitiligo, thyroid disease and other autoimmune conditions
How is alopecia areata diagnosed?
Clinical picture +/-
Trichoscopy - dermatoscope to examine the scalp
Skin biopsy + histopathology
How do you manage alopecia areata?
Regrowth is common, especially in early stages and with milder disease
Systemic therapy reserved for:
- > 20% scalp loss
- Rapid hair loss
- Chronic hair loss
- Severe distress
Topical:
- Ultrapotent topical steroids
- Minoxidil
- Dithranol
Intralesional corticosteroid injections:
- Triamcinolone acetonide SC (?) may speed up hair regrowth
Systemic corticosteroids - though not often given due to long term side effects
What is the non-pharmacological management of alopecia areata?
Hairpiece:
- Full wig = cap over whole head
- Partial wig = glued/clipped to hair
- Hair extensions = glued to existing fibres and removed after 8/52
Fake eyelashes and eyebrows also
What are the long term outcomes for alopecia areata?
40% with single patch of hair loss - full regrowth in 6/12
27% of multiple patches - full regrowth in 12/12
33% have chronic hair loss
Poor porgnostic factors:
- Younger age of onset
- Extensive disease
- Bald patch >1yr
- Ophiasis pattern, nail signs
- +ve FHx
What are some other causes of hair loss?
Medical:
- Thyroid disease
- Iron deficiency anaemia
- Secondary syphilis
- Lupus
Drugs:
- Cancer treatments (chemo/radiotherapy)
Hormonal changes (menopause, pregnancy)
Stress/emotional trauma
Trauma to hair/head; dyeing/hair treatments
Protein deprivation including strict dieting; dramatic weight loss
Natural ageing (especially in men)
