Topic Overview
What is alopecia areata?
Alopecia areata is a type of
hair loss that occurs when your
immune system mistakenly attacks
hair
follicles
, which is where hair growth begins. Experts do not know why
the immune system attacks the follicles. Alopecia areata is most common in
people younger than 20, but children and adults of any age may be affected.
What happens in alopecia areata?
Alopecia areata usually begins when clumps of hair fall out,
resulting in totally smooth, round hairless patches on the scalp. In some cases
the hair may become thinner without noticeable patches of baldness, or it may
grow and break off, leaving short stubs (called "exclamation point" hair).
Rarely, complete loss of scalp hair and body hair occurs. The hair loss often
comes and goes—hair will grow back over several months in one area but will
fall out in another area.
When alopecia areata results in patches of hair loss, the hair
usually grows back in 6 months to 1 year.1 Although
the new hair is usually the same colour and texture as the rest of the hair, it
sometimes is fine and white.
About 10% of people with this condition may never regrow
hair.2 You are more likely to have permanent hair loss
if you:
- Have a family history of the
condition.
- Have the condition at a young age (before
puberty) or for longer than 1 year.
- Have
an
autoimmune disease.
- Are prone to allergies
(atopy).
- Have extensive hair loss.
- Have abnormal colour,
shape, texture, or thickness of the fingernails or toenails.
Because hair is an important part of appearance, hair loss can
result in feeling unattractive.
In some people, the fingernails and toenails become pitted—they
look as if a pin had made many tiny dents in them. They may also look like
sandpaper.
How is alopecia areata diagnosed?
Alopecia areata is diagnosed through a medical history and
physical examination. Your health professional will ask you questions about
your hair loss, look at the pattern of your hair loss, and examine your scalp,
and may tug gently on a few hairs or pull some out.
If the reason for your hair loss is not clear, your health
professional may do tests to check for a disease that could be causing your
hair loss. Tests include:
- Hair analysis. Your health professional will
take a sample of your hair and examination it under a microscope. A scalp sample is
also sometimes taken.
- Blood tests, including testing for a specific
condition, such as an overactive or underactive thyroid gland (hyperthyroidism or
hypothyroidism).
How is it treated?
Because hair usually grows back within a year, you may decide not
to treat alopecia areata.
If you choose not to treat the condition and wait for your hair
to grow back, you may wish to:
- Wear hairpieces or hair weaves. Hairpieces
are made from human or synthetic hair that is implanted into a nylon netting.
Hairpieces may be attached to the scalp with glue, metal clips, or tape. Hair
weaving involves sewing or braiding pieces of longer hair into existing hair.
- Use certain hair care products and styling techniques. Hair care
products or perms may make hair appear thicker. Dyes may be used to colour the
scalp. However, continual use of perms or dyes may result in more hair loss.
The most common treatment for patchy hair loss is many injections
of
corticosteroids into the scalp, about
1 cm (0.4 in.) apart, every 4
to 6 weeks. Limited research reports that hair grows back at the site of
injection in some people.3
Contact immunotherapy may be the most effective treatment for
severe alopecia areata.1 A medication is "painted" on
the scalp once a week. Hair growth may appear within 3 months of beginning
treatment. A review of research on contact immunotherapy notes that about half
of those with severe alopecia areata had a good response, but how much hair
grew back varied widely.3 Side effects of contact
immunotherapy include a severe rash (contact
dermatitis) and swollen
lymph nodes, especially in the neck.
Other medications used to treat alopecia areata include minoxidil
(Rogaine), anthralin, and cyclosporine. Anthralin is sometimes used in
combination with minoxidil. These medications affect the immune system and may
stimulate hair growth, but they do not prevent hair loss.
How will alopecia areata affect my life?
Alopecia areata does not affect you as another condition might:
it is not painful, it does not make you feel sick, and it does not result in
serious health problems. You cannot spread it to other people, and it should
not interfere with school, work, or recreation.
If hair loss is making you feel unattractive, it is important to
talk to someone about it. A counsellor can help, as can talking to other people
with the same condition.