What is Alopecia Areata?

Definition and Mechanism

Alopecia areata is a chronic autoimmune disease in which the body's immune system mistakenly attacks hair follicles, causing hair loss in varying patterns and extents. It is not contagious and not life-threatening, but can significantly affect quality of life and self-image.

Types of Alopecia

• Alopecia Areata — Round patches of hair loss on scalp or body
• Alopecia Totalis — Complete loss of scalp hair
• Alopecia Universalis — Complete hair loss across the entire body, including eyebrows and eyelashes
• Ophiasis — Hair loss in strips along the scalp margins

How Common Is It?

Alopecia areata affects approximately 2% of the global population — about 160 million people worldwide. In Israel, an estimated 120,000–150,000 people suffer from the disease. It appears at all ages, but often begins before age 30. Men and women are affected equally.

Risk Factors

• Family history of alopecia areata
• Other autoimmune diseases (such as thyroid disease, type 1 diabetes, vitiligo)
• Acute psychological stress or traumatic event
• Young age at onset is associated with more challenging prognosis

Diagnosis

Diagnosis is usually made by a dermatologist based on clinical examination. Blood tests are sometimes done to rule out other conditions, and in some cases a scalp biopsy may be performed. A dermatoscope — a special magnifying device — helps the doctor examine follicle condition.

Disease Course

Alopecia areata has an unpredictable course. Some patients experience spontaneous remission — hair regrowth without treatment. Others experience recurrent episodes. About 30% of those diagnosed will suffer from chronic, prolonged disease. The good news: hair follicles are never completely destroyed, allowing potential for regrowth.