Alopecia areata is the name for patches of total hair loss.
Incidence and possible causes
There is no known cause for the condition, though about 20 percent of patients have a family history of alopecia. It is estimated that one person in a thousand will be affected at some stage in their lives, mainly during youth. Men and women are affected equally.
A positive family history indicates there might be a genetic predisposition to the condition.
The most favoured explanation is that alopecia areata is an auto-immune disorder, in which antibodies to the person’s own hair follicles are produced. Alopecia is also found with other auto-immune disorders, such as vitiligo and thyroiditis.
In susceptible persons, factors triggering an episode of alopecia are though to be:
Stress – especially sudden severe emotional stress,
Diagnosis and tests
Though any hairy area of the body can be affected, the typical patch of alopecia areata occurs on the scalp, is smooth, completely hairless, with short broken hairs around the edge of the “bald spot”. There may be more than one such bald spot, and the spots may join up to form a larger bald area. Very rarely, the whole scalp may be affected, or, even more rarely, the whole body.
The condition is not painful or life-threatening, and has mainly cosmetic implications.
The diagnosis of alopecia is mainly clinical – that is, based on examining the patient. In uncertain cases, a scalp biopsy may be taken (rare). Some blood tests may be considered, to establish whether there is another underlying auto-immune disease such as thyroiditis.
Treatment and outcome
The majority (up to 80 percent) of patients with small patches of alopecia will recover without treatment, within a year. Some patients may have relapses in the future.
If treatment is chosen, the most often prescribed medication is a steroid (like cortisone), which can be injected, taken by mouth or applied to the skin. Substances promoting hair growth, for instance Minoxidil, may be considered. Ultra-violet light therapy may be of benefit to some.
For large areas of hair loss in women, patients may opt to wear a wig as a temporary measure.
Dr AG Hall, Health24, January 2008