Alopecia areata

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 color 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 color, 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 exam 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 color 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 1cm 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 counselor can help, as can talking to other people with the same condition.

Citations

1. Springer K, et al. (2003). Common hair loss disorder. American Family Physician, 68(1): 93–102.

2. Habif TP (2004). Hair diseases. In Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 4th ed., pp. 834–863. Philadelphia: Mosby.

3. MacDonald Hull SP, et al. (2003). Guidelines for the management of alopecia areata. British Journal of Dermatology, 149: 692–699.