Alopecia Areata
Key points
- Alopecia areata is a skin disorder that causes hair loss, usually in patches, most often on the scalp.
- In its most common form, alopecia areata causes small round or oval patches of baldness on the scalp.
- Your doctor may suspect that you have alopecia areata based on your symptoms and, in some cases, your family history of the disorder.
- In most small patches of alopecia areata, the hair regrows within six to 12 months.
What Is It?
Alopecia areata is a skin disorder that causes hair loss, usually in patches, most often on the scalp. Usually, the bald patches appear suddenly and affect only a limited area. The hair grows back within 12 months or less. For some people, however, the problem can last longer and be more severe, causing total baldness (alopecia totalis) or total loss of body hair (alopecia universalis).
The cause of alopecia areata is probably an autoimmune reaction. This means the body's immune system incorrectly attacks the body's own cells. In the case of alopecia areata, the cells under attack are in the hair follicles (structures that grow hair), especially follicles within the scalp.
Genetic (inherited) factors may play a role, too, particularly when the disorder strikes those under age 30. Almost 40 percent of people under 30 with alopecia areata have at least one family member who has been diagnosed with the same disorder.
The risk of developing alopecia areata is unusually high in people who have asthma, hay fever, thyroid disease, vitiligo (a condition in which patches of skin lose their color), pernicious anemia and Down syndrome.
Although experts once believed episodes of alopecia areata could be triggered by stress, newer research has failed to prove that stress is a factor.
Approximately 1 percent to 2 percent of people in the United States develop alopecia areata at some time during their lives. In about 60 percent of cases, the first episode of hair loss occurs before age 20 and is followed by hair regrowth. However, it's common for the problem to come back, and new bald patches can develop at the same time older ones are regrowing hair.
Symptoms
In its most common form, alopecia areata causes small round or oval patches of baldness on the scalp. The area of bald skin looks smooth and normal. In most cases, there are no other scalp symptoms. Occasionally, there is mild itching, tingling, tenderness or a burning sensation in the affected area. Some people with alopecia areata also have abnormalities in the surface of their fingernails, such as tiny pits or dents, grooves, superficial splitting or an abnormal area of redness.
In rarer, more severe forms of the disorder, hair loss can involve the entire scalp or the entire body, including the eyebrows, eyelashes, beard, underarm hair and pubic hair (hair around the genitals).
Diagnosis
Your doctor may suspect that you have alopecia areata based on your symptoms and, in some cases, your family history of the disorder. To look for further evidence, your doctor will examine your scalp and pull gently on the hairs near the edge of the bald area. If these hairs come out very easily, the doctor will inspect them for structural abnormalities of the root or shaft. In some cases, a small skin biopsy of your scalp may confirm the diagnosis. In a biopsy, a small piece of skin is removed and examined in a laboratory.
Frequently asked questions
What is alopecia areata?
Alopecia areata is a skin disorder that causes hair loss, usually in patches, most often on the scalp. Usually, the bald patches appear suddenly and affect only a limited area. The hair grows back within 12 months or less. For some people, however, the problem can last longer and be more severe, causing total baldness (alopecia totalis) or total loss of body hair (alopecia universalis). The cause of alopecia areata is probably an autoimmune reaction. This means the body's immune system incorrectly attacks the body's own cells. In the case of alopecia areata, the cells under attack are in the hair follicles (structures that grow hair), especially follicles within the scalp.
What are the symptoms of alopecia areata?
In its most common form, alopecia areata causes small round or oval patches of baldness on the scalp. The area of bald skin looks smooth and normal. In most cases, there are no other scalp symptoms. Occasionally, there is mild itching, tingling, tenderness or a burning sensation in the affected area. Some people with alopecia areata also have abnormalities in the surface of their fingernails, such as tiny pits or dents, grooves, superficial splitting or an abnormal area of redness. In rarer, more severe forms of the disorder, hair loss can involve the entire scalp or the entire body, including the eyebrows, eyelashes, beard, underarm hair and pubic hair (hair around the genitals).
How is alopecia areata diagnosed?
Your doctor may suspect that you have alopecia areata based on your symptoms and, in some cases, your family history of the disorder. To look for further evidence, your doctor will examine your scalp and pull gently on the hairs near the edge of the bald area. If these hairs come out very easily, the doctor will inspect them for structural abnormalities of the root or shaft. In some cases, a small skin biopsy of your scalp may confirm the diagnosis. In a biopsy, a small piece of skin is removed and examined in a laboratory.
Written and revised by
Andrey Nailor, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
health.am provides general information, not medical advice. Always consult a qualified health professional about your own health.