Alopecia areata is a relatively common condition which may occur at any age in either sex. The prevalence of Alopecia areata in the UK population is around 0.15%.
It is a non-scaring condition which can affect:
- the hair follicles - damage is not permanent
- the nails - 10-30% of patients (1)
Alopecia areata can be categorized according to extent or pattern of hair loss
- Patchy - most common presentation with limited hair loss
- Extensive - over 50% hair loss
- Alopecia totalis - total loss of hair on the scalp
- Alopecia universalis - total loss of body hair
- Diffuse hair loss - can be seen occasionally
The cause is thought to be an autoimmune phenomenon as often; there is a co-existing autoimmune disease e.g. pernicious anaemia, thyroid disorders, vitiligo, diabetes.
There are lymphocytic infiltrates around the follicles, and a high prevalence of autoantibodies and abnormalities on the titres of circulating T lymphocytes (1).
Children and adolescents are affected more commonly with a peak age of onset between 15 and 29 years of age. In around 25% of the patients, a positive family history can be found (1).
Last reviewed 01/2018