Alopecia Areata

Question 1

What is alopecia areata?

Answer 1

Alopecia = hair loss

=> Alopecia areata = one or more round bald patches appear suddenly on the scalp.

Alopecia areata = autoimmune disease ; can also cause diffuse alopecia.

Question 2

Who is at risk of alopecia areata?

Answer 2

=> Affect males and females at any age

=> 50% starts in childhood

=> 80% before 40yrs

=> Family hx of alopecia areata ± other autoimmune disease in 10–25% of patients

=> At least 8 susceptibility genes have been detected.

=> Alopecia areata assoc. with higher rates of thyroid disease, vitiligo and atopic eczema

Question 3

What causes alopecia areata?

What can trigger alopecia areata?

Answer 3

Alopecia areata = autoimmune disorder

Histologically characterised by T cells around the hair follicles.
=> CD8+NK T cells release pro-inflammatory cytokines and chemokines that reject the hair

The onset or recurrence triggered by:

=> Viral infection
=> Trauma
=> Hormonal change
=> Emotional/physical stressors

Question 4

What are the clinical features of alopecia areata?

Answer 4

More severe disease assoc. with young age, concurrent atopic eczema and chromosomal abnormalities

Most patients = no symptoms and a bald patch or thinning hair
=> incidental finding often by a hairdresser

Trichodynia = burning, prickly discomfort in the affected areas

Question 5

What are the complications of alopecia areata?

Answer 5

Alopecia = temporary or persistent

More severe and persistent disease = depression & anxiety

Patients should be assessed for atopy, vitiligo, thyroid disease, and other autoimmune conditions

Question 6

How is alopecia areata diagnosed?

Answer 6

Alopecia areata = clinical diagnosis

Other tests used to confirm diagnosis:

=> Trichoscopy (use of a dermatoscope to examine hair and scalp)

=> Skin biopsy (histopathology)

Question 7

What are the 6 different presentations of autoimmune alopecia?

Answer 7

1. Patchy alopecia areata
2. Alopecia totalis
3. Alopecia universalis
4. Ophiasis
5. Diffuse alopecia areata
6. Alopecia areata of the nails

Question 8

What is patchy alopecia areata?

Answer 8

Patchy alopecia areata:

=> affects any hair-bearing area, most often the scalp, eyebrows, eyelashes and beard

Patchy alopecia areata has three stages:

i. Sudden loss of hair
ii. Enlargement of bald patch or patches
iii. Regrowth of hair

The bald areas may have a smooth surface, completely devoid of hair or with scattered ‘exclamation mark’ hairs.

Question 9

What is alopecia totalis?

Answer 9

Alopecia totalis:

=> Affects ~`5% of patients with autoimmune hair loss

=> All / nearly all scalp hair is lost

Question 10

What is alopecia universalis?

Answer 10

Alopecia universalis:

=> Affects less than 1%

=> All hair or nearly all hair on the entire body is lost.

Question 11

What is ophiasis?

Answer 11

Ophiasis:

=> pattern of alopecia areata affecting occipital and lateral scalp

Question 12

What is diffuse alopecia areata?

Answer 12

Diffuse alopecia areata
aka called alopecia areata incognita:

=> Presents with sudden diffuse alopecia

=> Persisting hair is grey

Question 13

What is alopecia areata of the nails?

Answer 13

Alopecia areata of the nails:

=> Affects 10–50% of those with alopecia areata

=> Regular pitting and ridging of the nail

=> May also cause koilonychia, 
trachyonychia, 
Beau lines, 
onychorrhexis, onychomadesis, 
onycholysis,
red spots on the lunula

Question 14

What are the poor prognostic features of alopecia areata?

Answer 14

Young age at onset

Extensive disease

Bald patches persisting for more than 1 year

An ophiasis pattern of hair loss

Alopecia areata of the nails

The onset of alopecia areata before puberty

Family hx of alopecia areata

Personal or family hx of other autoimmune diseases

Down syndrome

Question 15

What is the treatment for alopecia areata?

Answer 15

No reliable cure yet.

Topical treatment or I.V. with steroids

Immunotherapy with sensitisers i.e. diphencyprone

JAK/STAT inhibitors in moderate-severe alopecia areata i.e. oral tofacitinib

Question 16

How do you manage alopecia areata?

Answer 16

Counselling:
=> due to major psychosocial impact

Camouflaging hair loss:
=> wig
=> artificial eyelashes
=> eyebrow tattoes

Question 17

In many patients with a single bald patch, spontaneous regrowth occurs within a year.

Answer 17

=> 40% of patients with a single patch of hair loss have full hair regrowth within 6 months.

=> 27% of patients with multiple patches of hair loss have full regrowth within 12 months.

=> 33% of patients with alopecia areata have chronic hair loss.